Development of a Sensitive Somatostatin Radioimmunoassay and its Application to Plasma of Stressed and Non-Stressed Rats

The availability of antibodies against the ovine corticotropin releasing factor ( 0 , which cross-react with a CRF-like immunoreactivity (CRF-LI) in the rat, has enabled us to develop a radioimmunoassay (RIA) for rat CRF-LI in plasma and crude hypothalamic extracts. IZ51-Tyr CRF 1-41 was used as the tracer, and synthetic ovine CRF as the reference hormone. The precision profile of the assay indicates a high degree of reproducibility except for the lower dose range. The minimum detectable dose was 20 pg/tube. This assay can detect differences in plasma CRF-LI levels after various manipulations that simultaneously alter the ACTH levels in plasma. A wide range of CRF concentrations has been found in plasma of normal rats. Caution should be exercised in the interpretation of the values obtained since an ovine RIA system was used.

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“…On the other hand, plasma CRF levels are similar to those found for somatostatin (24). This hormone also has peripheral sources of secretion.…”

Section: Plasma Crf-li In Cpz-m-n-treated Ratssupporting

confidence: 70%

Radioimmunoassay of CRF-Like Material in Rat Plasma: Validation of the Method

Torres‐Alemán

Vígh

Merchenthaler

et al. 1983

Experimental Biology and Medicine

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“…Recovery of added SRIF was 90%. The radioimmunoassay represents (21). 100 µl of sample, and 100 µl of antiserum (working dilution: 1:250,000) were incubated for 24 h, then 100 µl of 125 I-Tyr-SRIF were added and incubated for an additional 24 h. Free antigen was separated from bound by adding 1 ml of dextran T70 coated charcoal.…”

Section: Srifli Radioimmunoassaymentioning

confidence: 99%

“…The detection limit (lowest detectable level) was 5 pg/ml. Cross reactivity was previously described (21).…”

Section: Srifli Radioimmunoassaymentioning

confidence: 99%

Substance P Mechanism in Cluster Headache: Evaluation in Plasma and Cerebrospinal Fluid

et al. 1985

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Substance P (SP), present in sensory afferent neurons, seems to process nociceptive information in the trigeminal system. SP, released from peripheral trigeminal endings, causes typical cluster headache (CH) signs, e.g. vasodilatation, conjunctival and nasal edema and miosis. Opiates and somatostatin (SRIF), both active in relieving CH attack, inhibit SP release from the central and peripheral trigeminal system. In the present study, plasma and cerebrospinal fluid (CSF), SP-like immunoreactivity (SPLI) and enkephalinase activity (EKA), and plasma SRIF-like immunoreactivity (SRIFLI) have been evaluated during spontaneous and histamine induced attacks in the cluster phase. During the histamine provoked attacks, CSF SPLI and plasma SRIFLI and EKA were unchanged, while plasma SPLI decreased significantly. During spontaneously occurring attacks, plasma SRIFLI was found to be unmodified and a significant lowering of SPLI was detected when compared with controls. Moreover, both during and between attacks in the cluster phase, plasma EKA was increased in comparison with the values in controls. It remains to be seen whether variations of plasma SPLI and EKA levels play a role in the CH mechanism.

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“…Kiel. FRG) as described by us [9], but modi fied by the use of an acidic (pH 4) assay diluent capa ble of reducing unspecific interference with the anti gen-antibody reaction by unknown tissue and plasma factors.…”

Section: Analysesmentioning

confidence: 99%

Pancreatic Duct Occlusion in the Rat – Short-Term Effects on Oral Glucose Tolerance and Short- and Long-Term Effects on Hormone Content of the Pancreas

Klein¹,

Engelhardt²,

Stolte

et al. 1984

Eur Surg Res

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In a short-term (14 days) and a long-term (84 days) experiment after pancreatic duct occlusion in the rat, we measured the insulin, glucagon and somatostatin content of the pancreas; in the short-term experiment, in addition, we performed an oral glucose tolerance test on the 14th day. Exocrine pancreatic function in the short-term study was monitored on the 9th day – in the long-term study on the 21 st day. In the long-term study, the pancreatic organ was also examined histologically. Occlusion of the pancreatic duct considerably reduces exocrine function. This accords with the histologically observed atrophy of the exocrine parenchyma, above all in the body and tail (after 84 days). 14 days after occlusion, basal plasma glucose and insulin was about the same as in the sham-operated rats. Incremental insulin after the glucose load in occluded rats was delayed for about 30 min, but the pattern of plasma glucose was only insignificantly altered as compared with the sham-operated controls. The insulin content of the pancreas on days 14 and 84 after occlusion was increased, glucagon and somatostatin unchanged. We conclude, that (a) intraductal occlusion of the pancreas is a suitable tool for inducing an atrophy of the exocrine pancreas; (b) in the short-term, after the duct occlusion, oral glucose tolerance is preserved, but the passage of insulin into the blood is delayed and is associated with a high level of insulin in the pancreas; the cause or causes of this coincidence is/are unknown.

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Development of a Sensitive Somatostatin Radioimmunoassay and its Application to Plasma of Stressed and Non-Stressed Rats

Cited by 21 publications

References 3 publications

Radioimmunoassay of CRF-Like Material in Rat Plasma: Validation of the Method

Radioimmunoassay of CRF-Like Material in Rat Plasma: Validation of the Method

Substance P Mechanism in Cluster Headache: Evaluation in Plasma and Cerebrospinal Fluid

Pancreatic Duct Occlusion in the Rat – Short-Term Effects on Oral Glucose Tolerance and Short- and Long-Term Effects on Hormone Content of the Pancreas

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Development of a Sensitive Somatostatin Radioimmunoassay and its Application to Plasma of Stressed and Non-Stressed Rats

Cited by 21 publications

References 3 publications

Radioimmunoassay of CRF-Like Material in Rat Plasma: Validation of the Method

Radioimmunoassay of CRF-Like Material in Rat Plasma: Validation of the Method

Substance P Mechanism in Cluster Headache: Evaluation in Plasma and Cerebrospinal Fluid

Pancreatic Duct Occlusion in the Rat &ndash; Short-Term Effects on Oral Glucose Tolerance and Short- and Long-Term Effects on Hormone Content of the Pancreas

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Pancreatic Duct Occlusion in the Rat – Short-Term Effects on Oral Glucose Tolerance and Short- and Long-Term Effects on Hormone Content of the Pancreas