saporin

Li AJ, Wang Q, Dinh TT, Wiater MF, Eskelsen AK, Ritter S (2013) Hindbrain catecholamine neurons control rapid switching of metabolic substrate use during glucoprivation in male rats. Endocrinology 154(12):4570-4579. doi: 10.1210/en.2013-1589

Summary: Previous work has shown that corticosterone secretion in response to glucoprivation is at least in part controlled by hindbrain catecholamine neurons in the paraventricular nucleus of the hypothalamus (PVH). In this work the authors investigate the metabolic consequences of lesioning these neurons. Rats received bilateral 82-ng infusions of Anti-DBH-SAP (Cat. #IT-03) into the PVH. Saporin (Cat. #PR-01) was used as a control. Although lesioned animals had the same energy expenditure and locomotor activity as controls, they also had a higher respiratory exchange ratio, indicating a reduced ability to switch from carbohydrate to fat metabolism in response to glucoprivation.

Related Products: Anti-DBH-SAP (Cat. #IT-03), Saporin (Cat. #PR-01)

da Silva EF, Freiria-Oliveira AH, Custodio CH, Ghedini PC, Bataus LA, Colombari E, de Castro CH, Colugnati DB, Rosa DA, Cravo SL, Pedrino GR (2013) A1 noradrenergic neurons lesions reduce natriuresis and hypertensive responses to hypernatremia in rats. PLoS One 8(9):e73187. doi: 10.1371/journal.pone.0073187

Summary: Using bilateral 63-ng injections of Anti-DBH-SAP (Cat. #IT-03) into two levels of the caudal ventrolateral medulla, the authors assessed several pressor responses to infusion of hypertonic saline. Saporin (Cat. #PR-01) was used as a control. The results suggest that medullary noradrenergic A1 neurons are involved in the regulation of some responses to acute changes in body fluid composition.

Related Products: Anti-DBH-SAP (Cat. #IT-03), Saporin (Cat. #PR-01)

Chang ST, Liu YP, Huang CL, Wang PY, Tung CS (2013) Implication of cerebral dopamine-beta hydroxylase for cardiovascular and mood regulation in rats. Chin J Physiol 56(4):209-218. doi: 10.4077/CJP.2013.BAB103

Summary: The ascending fibers affected by norepinephrine are involved in a variety of processes, including emotion, anxiety, and regulation of central autonomic outflows such as cardiovascular regulation and energy balance. The authors examined whether the loss of norephinephrine would cause autonomic failure in cardiovascular regulation. Rats received a single intraventricular injection of anti-DBH-SAP (Cat. #IT-03). Saporin (Cat. #PR-01) was used as a control. The results demonstrate that norepinephrine deficits in the brain influence reduction of excitatory responses to orthostatic stress.

Related Products: Anti-DBH-SAP (Cat. #IT-03), Saporin (Cat. #PR-01)

Shia WW, Bailey RC (2013) Single domain antibodies for the detection of ricin using silicon photonic microring resonator arrays. Anal Chem 85(2):805-810. doi: 10.1021/ac3030416 PMID: 23268548

Summary: A major hurdle to clear in the fight against bioterrorism is the ability to identify various biowarfare agents. One of the more difficult substances to identify is ricin. This work describes the use of single domain antibodies to identify ricin in a microring resonator array assay. Saporin (Cat. #PR-01) along with affinity purified chicken anti-saporin (Cat. #AB-17AP) were used as controls when constructing the assay. The results demonstrate the feasibility of using microring resonator arrays for the detection of biowarfare agents.

Related Products: Saporin Chicken Polyclonal, affinity-purified (Cat. #AB-17AP), Saporin (Cat. #PR-01)

Ferrini F, Trang T, Mattioli TA, Laffray S, Del’Guidice T, Lorenzo LE, Castonguay A, Doyon N, Zhang W, Godin AG, Mohr D, Beggs S, Vandal K, Beaulieu JM, Cahill CM, Salter MW, De Koninck Y (2013) Morphine hyperalgesia gated through microglia-mediated disruption of neuronal Cl(-) homeostasis. Nat Neurosci 16(2):183-192. doi: 10.1038/nn.3295

Summary: Although morphine is the drug of choice in dealing with chronic pain, it paradoxically can produce a hyperalgesic state. The authors examined the issue from several different angles. One method was to eliminate spinal microglia of rats through the intrathecal application of 16-32 μg of Mac-1-SAP (Cat. #IT-33). 20 μg of saporin (Cat. #PR-01) was used as a control. It was found that P2X4 receptors expressed by microglia were necessary for the development of morphine hyperalgesia, but not morphine tolerance.

Related Products: Mac-1-SAP rat (Cat. #IT-33), Saporin (Cat. #PR-01)

Read the featured article in Targeting Trends.

Daniels-Wells TR, Helguera G, Rodriguez JA, Leoh LS, Erb MA, Diamante G, Casero D, Pellegrini M, Martinez-Maza O, Penichet ML (2013) Insights into the mechanism of cell death induced by saporin delivered into cancer cells by an antibody fusion protein targeting the transferrin receptor 1. Toxicol In Vitro 27(1):220-231. doi: 10.1016/j.tiv.2012.10.006

Summary: The antibody-avidin fusion protein ch128.1Av has been shown to target the human transferrin receptor 1 (TfR1) and kill malignant B cells by blocking the use of iron. Combination of this construct with a mono-biotinylated saporin custom conjugate produces an iron-independent toxicity to TfR1-expressing cells, even those that are resistant to ch128.1Av alone. The saporin-containing conjugate induces a transcriptional response consistent with oxidative stress and DNA damage. The data also show that the saporin conjugate is not toxic to human hematopoeietic stem cells.

Usage: An antibody-avidin fusion protein (ch128.1Av) was mixed with MonoBiotin-ZAP to make an immunotoxin that targets the human transferrin receptor 1 (TfR1).

Related Products: MonoBiotin-ZAP (Cat. #BT-ZAP), Custom Conjugates

Savage S, Mattsson A, Olson L (2012) Cholinergic denervation attenuates phencyclidine-induced c-fos responses in rat cortical neurons. Neuroscience 216:38-45. doi: 10.1016/j.neuroscience.2012.04.064

Summary: Phenylcyclidine (PCP) has been used to model aspects of schizophrenia in animals. 81 ng of 192-IgG-SAP (Cat. #IT-01) was injected into the nucleus basalis magnocellularis of rats to assess the effects of low dose PCP in a cholinergically-deprived system. Saporin (Cat. #PR-01) was used as a control. Results demonstrate basalocortical cholinergic neurons are necessary for PCP to have full effect.

Related Products: 192-IgG-SAP (Cat. #IT-01), Saporin (Cat. #PR-01)

Q: What is the LD50 of saporin in mice? Do you have references for this?

A: Thank you for your question. It is very helpful to have this information to calculate the appropriate dose for systemic administration.

According to the work of Thorpe et al., saporin alone has an acute LD50, when delivered intravenously, of 6.8 mg/kg in mice. Histologic examination of kidneys from mice receiving near-lethal doses of saporin revealed necrosis of the convoluted tubules. Other major organs had only minor changes.

Once saporin is attached to an immunoglobulin, the LD50 drops dramatically to 1.0 mg/kg in systemic administration. Near-lethal doses of the conjugates, by contrast to saporin alone, inflicted major damage to the liver and spleen of the mice while the kidneys (and other organs) appeared normal under histologic examination.

References

1. Thorpe PE et al. An immunotoxin composed of monoclonal anti-thy 1.1 antibody and a ribosome-inactivating protein from Saponaria officinalis: potent antitumor effects in vitro and in vivo. J Natl Cancer Inst 75:151-159, 1985.

Sikandar S, Bannister K, Dickenson AH (2012) Brainstem facilitations and descending serotonergic controls contribute to visceral nociception but not pregabalin analgesia in rats. Neurosci Lett 519(1):31-36. doi: 10.1016/j.neulet.2012.05.009

Summary: Neurons in the rostral ventromedial medulla (RVM) are classified as ON, OFF, or NEUTRAL based on firing patterns in response to noxious somatic stimulation. ON cells express μ-opioid receptors, and are therefore a target for dermorphin-SAP (Cat. #IT-12). The authors injected the RVM of rats with 3 pmol of dermorphin-SAP; Saporin (Cat. #PR-01) was used as a control. Results show the μ-opioid receptor population is not needed for the function of analgesics through the serotonergic system.

Related Products: Dermorphin-SAP / MOR-SAP (Cat. #IT-12), Saporin (Cat. #PR-01)

Pedrino GR, Freiria-Oliveira AH, Almeida Colombari DS, Rosa DA, Cravo SL (2012) A2 noradrenergic lesions prevent renal sympathoinhibition induced by hypernatremia in rats. PLoS One 7(5):e37587. doi: 10.1371/journal.pone.0037587

Summary: It is thought that renal sympathetic nerve activity is a key component of the response to acute or chronic elevated concentrations of saline in the blood stream. The authors investigated what neurons are involved in the central control of these responses. Rats received bilateral 6.3 ng injections of anti-DBH-SAP (Cat. #IT-03) into the nucleus of the solitary tract. An equimolar amount (1.3 ng) of saporin (Cat. #PR-01) was used as a control. Loss of the A2 noradrenergic neurons altered the renal sympathetic nerve activity response to elevated saline, suggesting that these neurons help regulate the extracellular fluid compartment.

Related Products: Anti-DBH-SAP (Cat. #IT-03), Saporin (Cat. #PR-01)