Somatostatin (SRIF) is a putative peptide neurotransmitter that may interact with brain capillaries following neurosecretion of the peptide. The present studies investigate the binding and metabolism of SRIF analogues in isolated bovine brain microvessels. 125I-[Tyr1]SRIF was rapidly degraded by capillary aminopeptidase with a half-time of approximately 3 min at 23 degrees C. The microvessel am...

We investigated the effects of inorganic lead upon calcium-, phospholipid-dependent protein kinase (protein kinase C) in brain microvessels isolated from 6-day-old rat pups. We found that (a) in broken cell preparations, lead at micromolar concentrations activates this enzyme to an extent equivalent to that of micromolar calcium (10.3 +/- 1.3 and 9.2 +/- 1.6 pmol/mg/min, respectively) and (b) p...

related enzymes in isolated brain microvessels. Proc Natl Acad Sci USA 72: 4622, 1975 32. Palmer GC: /3-adrenergic receptors mediate adenylate cyclase responses in rat cerebral capillaries. Neuropharmacology 19: 17, 1980 33. Herbst TJ, Raichle ME, Ferrendelli JA: ,3-adrenergic regulation of adenosine 3'-5'-monophosphate concentration in brain microvessels. Science 204: 330, 1979 34. MacKenzie E...