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Recent progress in research on ribosome inactivating proteins.
Ng TB, Wong JH, Wang H (2010) Recent progress in research on ribosome inactivating proteins. Curr Protein Pept Sci 11(1):37-53. doi: 10.2174/138920310790274662
Summary: This review discusses recent literature on ribosome inactivating proteins including the use of saporin-based conjugates in neuroscience and cancer research. Brief descriptions of research done using 192-IgG-SAP (Cat. #IT-01), OX7-SAP (Cat. #IT-02), dermorphin-SAP (Cat. #IT-12), anti-SERT-SAP (Cat. #IT-23), SSP-SAP (Cat. #IT-11), anti-DBH-SAP (Cat. #IT-03), CTB-SAP (Cat. #IT-14), and other conjugates are provided along with basic information about ribosome inactivating proteins.
Related Products: 192-IgG-SAP (Cat. #IT-01), OX7-SAP (Cat. #IT-02), Dermorphin-SAP / MOR-SAP (Cat. #IT-12), Anti-SERT-SAP (Cat. #IT-23), SSP-SAP (Cat. #IT-11), Anti-DBH-SAP (Cat. #IT-03), CTB-SAP (Cat. #IT-14)
Analysis of inhibitory phase of formalin test: Effects of specific neural lesions
Wiley RG, Moore SA, Kline IV RH (2008) Analysis of inhibitory phase of formalin test: Effects of specific neural lesions. Neuroscience 2008 Abstracts 772.4/MM19. Society for Neuroscience, Washington, DC.
Summary: The formalin test has been widely used as a model of persistent pain. The 90 mins of formalin-induced nocifensive responding can be divided into two phases (phase 1, first ~10 mins; phase 2, last ~60 mins) separated by a period of reduced responding (interphase, IP), that has received relatively little attention. Behavioral inhibition during the IP of the formalin test has been associated with electrophysiological evidence of inhibition of dorsal horn nociceptive neurons (Henry et al, Pain, 82:57, 1999), probably due, at least in part, to local spinal mechanisms. Behavioral inhibition during IP has been shown to be enhanced by morphine and suppressed by naloxone. In the present study, we sought to determine the effect of selective depletion of specific dorsal horn interneurons known to be involved in nociception, i.e. neurons expressing NPY1R, GalR1 or MOR, or selective destruction of cerebral noradrenergic neurons or spinal cord projecting 5-HT neurons on formalin-induced nociceptive behavior, with particular attention to IP. Type-selective lesions were produced by lumbar intrathecal injection of NPY-saporin, galanin-saporin or dermorphin-saporin, respectively. Cerebral noradrenergic neurons and spinally projecting 5-HT neurons were destroyed using the immunotoxins, anti-DBH-saporin (intracerebroventricular) or anti-SERT-saporin (lumbar intrathecal), respectively. Partial loss of dorsal horn interneurons expressing NPY1R or GalR1 decreased nocifensive responding during IP and phase 2 of the formalin test, while partial loss of MOR-expressing dorsal horn interneurons increased nocifensive responding during IP and during phase 2. Both antiDBH-sap and antiSERT-sap decreased responding during IP, without effects on either phase 1 or 2. These results suggest that the apparent anti-nociception during IP and phase 2 produced by loss of NPY1R- and GalR1-expressing dorsal horn neurons is due to increased inhibition over excitation/facilitation of nociceptive projection neurons, whereas depletion of MOR-expressing interneurons produces the opposite effect. The apparent enhanced nociception during IP, but not phase I and II, produced by anti-DBH-sap and anti-SERT-sap suggests that these neural systems serve to enhance the excitability of nociceptive projection neurons during the formalin IP. Electrophysiologic and pharmacologic studies of formalin IP in selectively lesioned animals combined with the above behavioral findings may reveal new insights into endogenous modulation of nocifensive motor responses and/or nociception.
Related Products: NPY-SAP (Cat. #IT-28), Anti-SERT-SAP (Cat. #IT-23), Galanin-SAP (Cat. #IT-34), Anti-DBH-SAP (Cat. #IT-03), Dermorphin-SAP / MOR-SAP (Cat. #IT-12)
Intra cisterna magna and Rostral ventromedial medulla injection of anti-Serotonin transporter-Saporinpertussis enhanced somatotopically different c-Fos expression and pain related behaviour in the medullary dorsal horn in rats
Sugiyo S, Uehashi D, Masawaki A, Ohyamaguchi A, Abe T, Yonehara N, Takemura M (2008) Intra cisterna magna and Rostral ventromedial medulla injection of anti-Serotonin transporter-Saporinpertussis enhanced somatotopically different c-Fos expression and pain related behaviour in the medullary dorsal horn in rats. Neuroscience 2008 Abstracts 369.11/KK23. Society for Neuroscience, Washington, DC.
Summary: The rostral ventromedial medulla (RVM) is a key center in descending pain modulator, which contain serotonergic neurons having descending projectional terminals in the trigeminal caudal nucleus (Vc; medullary dorsal horn). The functional significance of serotonergic neurons in the RVM is largely unknown. Pretreatment with anti IgG serotonin transporter conjugated with neurotoxin, saporin (anti-SERT-SAP; Advanced Targeting Systems) selectively eliminates cells bearing serotonin transporter, namely serotonergic neurons. 2-4 weeks after injection of anti-SERT-SAP (0.5 µM, 10 nl) into the RVM, the number of serotonin-immunoreactive (IR) cells in the RVM significantly decreased. Formalin injection (1,25% in saline) into the upper lip induced biphasic nociceptive pain-related behavior (PRB). In the rats anti-SERT-SAP-pretreated into the RVM, showed decreased the number of formalin-induced PRB at 1st and 2nd phase compared with the Blank-SAP-pretreated control. 2-4 weeks after intra cisterna magna (CM) pretreatment of anti-SERT-SAP(5 µM, 5 µl), the number of serotonin-IR cells in the RVM also reduced. In stark contrast to the results of pretreatment into the RVM, anti-SERT-SAP-pretreated rats into the CM increased the number of formalin-induced PRB at 1st and 2nd phase. These results indicate that serotonergic neurons in the RVM are constituted by two groups, 1) having pronociceptive function and 2) antinociceptive function projecting to the superficial layers of the Vc.
Related Products: Anti-SERT-SAP (Cat. #IT-23)
Central chemoreception is a complex system function that involves multiple brain stem sites.
Nattie E, Li A (2009) Central chemoreception is a complex system function that involves multiple brain stem sites. J Appl Physiol 106:1464-1466. doi: 10.1152/japplphysiol.00112.2008
Summary: This short review discusses central chemoreception and the different neuronal subtypes that play roles in this process. The use of anti-SERT-SAP (Cat. #IT-23) and anti-DBH-SAP (Cat. #IT-03) is mentioned in the context of how the loss of each of these cell types affects CO2 response in rats.
Related Products: Anti-SERT-SAP (Cat. #IT-23), Anti-DBH-SAP (Cat. #IT-03)
Raphe Magnus Nucleus is involved in ventilatory but not hypothermic response to CO2.
Dias MB, Nucci TB, Margatho LO, Antunes-Rodrigues J, Gargaglioni LH, Branco LG (2007) Raphe Magnus Nucleus is involved in ventilatory but not hypothermic response to CO2. J Appl Physiol 103(5):1780-1788. doi: 10.1152/japplphysiol.00424.2007
Summary: In this work the authors investigated the role that serotonergic neurons in the Raphe Magnus Nucleus (RMg) play in ventilatory and thermal responses to hypercapnia. 0.1 µl of 1 µM anti-SERT-SAP (Cat. #IT-23) was injected into the RMg of rats. Mouse IgG-SAP (Cat. #IT-18) was used as a control. Lesioned animals had a decreased ventilatory response to CO2, but hypercapnia-induced hypothermia was not affected. The data indicate that RMg serotonergic neurons contribute to CO2 ventilatory response but not to maintenance of ventilation.
Related Products: Anti-SERT-SAP (Cat. #IT-23), Mouse IgG-SAP (Cat. #IT-18)
Ketanserin-induced baroreflex enhancement in spontaneously hypertensive rats depends on central 5-HT(2A) receptors.
Shen FM, Wang J, Ni CR, Yu JG, Wang WZ, Su DF (2007) Ketanserin-induced baroreflex enhancement in spontaneously hypertensive rats depends on central 5-HT(2A) receptors. Clin Exp Pharmacol Physiol 34:702-707. doi: 10.1111/j.1440-1681.2007.04626.x
Summary: Ketanserin is an anytihypertensive drug that effectively lowers blood pressure, decreases blood pressure variability, and enhances blood pressure response in spontaneously hypertensive rats. Using the fact that ketanserin is a selective 5-HT2A antagonist the authors investigated which of these effects utilized the 5-HT2A receptor. Following a 5 nmol ventricular injection of anti-SERT-SAP (Cat. #IT-23) the blood pressure parameters modified by ketanserin were monitored. The data suggest that the baroreflex sensitivity-enhancing effects of ketanserin use the 5-HT2A pathway, but antihypertensive effects follow a different route.
Related Products: Anti-SERT-SAP (Cat. #IT-23)
Effect of the destruction of cells containing the serotonin reuptake transporter on urethrogenital reflexes.
Gravitt K, Marson L (2007) Effect of the destruction of cells containing the serotonin reuptake transporter on urethrogenital reflexes. J Sex Med 4:322-331. doi: 10.1111/j.1743-6109.2007.00436.x
Summary: Using the fact that the urethrogenital (UG) reflex is an autonomic and somatic response, the authors developed a model for ejaculatory-like reflexes. Anti-SERT-SAP (Cat. #IT-23) was bilaterally injected into the ventrolateral medulla of rats. 80 nl of a 1 µM solution removed inhibition of the UG reflex after acute spinal cord transection, while this reflex could not be evoked in control animals. The data suggest that SERT-expressing neurons in the ventral medulla are involved with the inhibition of UG reflex.
Related Products: Anti-SERT-SAP (Cat. #IT-23)
Featured Article: Targeted toxins in pain
Wiley RG (2006) Featured Article: Targeted toxins in pain. Targeting Trends 7(2)
Related Products: 192-IgG-SAP (Cat. #IT-01), Anti-DBH-SAP (Cat. #IT-03), Anti-SERT-SAP (Cat. #IT-23), SP-SAP (Cat. #IT-07), SSP-SAP (Cat. #IT-11), Dermorphin-SAP / MOR-SAP (Cat. #IT-12),
Neurotoxic lesions of serotonin cells in the dorsal raphe reduce compulsive-like nest building in mice
Greene DM, Castillo MR, Alexander KA, McMahan A, Raap DK, Bult-Ito A (2005) Neurotoxic lesions of serotonin cells in the dorsal raphe reduce compulsive-like nest building in mice. Neuroscience 2005 Abstracts 796.10. Society for Neuroscience, Washington, DC.
Summary: Bi-directional selection for thermoregulatory nest-building behavior in house mice (Mus musculus) has resulted in a 40-fold difference in the amount of cotton used for nest-building between the high and the low selected lines (big and small nest-builders, respectively). The efficacy of serotonin re-uptake inhibitors (SSRIs), especially fluoxetine, for the treatment of obsessive-compulsive disorder (OCD) indicates a serotonergic involvement in the disorder. The repetitive nest-building behavior, characteristic of the big nest-builders, is a compulsive-like behavior that is responsive to SSRI treatment. We investigated the functional involvement of serotonergic pathways in excessive, repetitive nest-building behavior in mice by lesioning serotonergic cells in the dorsal raphe using the neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) or SERT-saporin (Advanced Targeting Systems). 5,7-DHT lesioned mice had a significant decrease in the number of serotonin-stained cells in the dorsal raphe. No decrease was noted in serotonin staining after lesions performed with the SERT-saporin neurotoxin. Mice with successful 5,7-DHT lesions also significantly decreased compulsive-like nest-building as compared to sham and non-surgery controls. These data taken together with additional findings in these mice support the involvement of serotonin pathways in OCD. This data further supports the big nest-builders as a potentially valuable animal model of compulsive behaviors in humans and a means to more clearly identify neurobiological pathways involved in OCD.
Related Products: Anti-SERT-SAP (Cat. #IT-23)
Effect of removal of neurons expressing serotonin reuptake transporter on male sexual reflexes
Gravitt KC, Cai RS, Marson L (2004) Effect of removal of neurons expressing serotonin reuptake transporter on male sexual reflexes. Neuroscience 2004 Abstracts 998.2. Society for Neuroscience, San Diego, CA.
Summary: Ejaculatory reflexes are regulated by spinal circuits that are tonically inhibited or facilitated by specific regions of the brain. Serotonin can facilitate or inhibit sexual responses depending on the site of action and the predominate receptor subtype involved. Sexual function, in particular ejaculation, can be reduced by administration of serotonin reuptake inhibitors (SSRI’s). The urethrogenital (UG) reflex comprises erections, rhythmic contractions of perineal muscles and ejaculation in male rats. We previously demonstrated that a direct pathway from the nucleus paragigantocellularis to the lumbosacral cord is involved in regulating the tonic inhibition of UG reflexes. Neurons in the ventral medulla contain serotonin and removal of serotonin inputs in the spinal cord allow the UG reflex to be exposed. The present study examined the effect of specific lesions of ventral medullary neurons containing the serotonin reuptake transporter (SERT) on sexual reflexes. Anti-SERT-saporin (50-100nl, 1uM) was injected bilaterally into the nPGi of male rats. Ten-fourteen days following surgery, animals were deeply anesthetized and the presence of the UG reflex examined. Urethral stimulation was performed before and after cutting the spinal cord (SCT) and recordings made from the bulbospongiosus muscle. Following the experiment immunocytochemical localization of serotonin was examined. In control rats the UG reflex was not present before SCT. In 50% of males that received anti-SERT-saporin the UG reflex was exposed before SCT. Responses after spinal cord transection were similar in all groups. Rats treated with ant-SERT-saporin showed a significant reduction in the number of serotonin containing neurons and a decrease in the intensity staining in the nPGi, parapyramidal region and medullary raphe. These studies suggest that neurons containing serotonin reuptake transporter systems are involved inhibiting male sexual reflexes.
Related Products: Anti-SERT-SAP (Cat. #IT-23)