Mechanisms underlying intracisternal TRH-induced stimulation of gastric acid secretion in rats.

The neurohumoral pathways mediating intracisternal TRH-induced stimulation of gastric acid secretion were investigated. In urethane-anesthetized rats, with gastric and intrajugular cannulas, TRH or the analog [N-Val2]-TRH (1 microgram) injected intracisternally increased gastric acid output for 90 min. Serum gastrin levels were not elevated significantly.

Spantide: failure to antagonize bombesin-induced stimulation of gastrin secretion in dogs.

Spantide ([d-Arg1, d-Trp7,9, Leu11] substance P) was shown to function not only as a substance P receptor antagonist but also as a bombesin receptor antagonist. This study examined the effects of spantide on intravenous bombesin-induced stimulation of gastrin and acid secretion. Dogs were infused with spantide (1 or 10 nmol kg 1 hr 1) or saline and bombesin (60 pmol kg-1 hr-1), and the gastric acid and plasma gastrin responses were monitored.

Cerebroventricular bombesin inhibits gastric acid secretion in dogs.

Bolus injections of bombesin into a lateral cerebral ventricle of conscious beagle dogs inhibited pentagastrin-stimulated gastric acid secretion from both the innervated stomach (gastric fistula) and the vagally denervated Heidenhain pouch in a dose dependent manner. Bombesin (300 ng/kg), injected into the lateral ventricle, inhibited acid secretion from the gastric fistula and Heidenhain pouch by 66% +/- 5% and 93% +/- 4%, respectively. Central administration of bombesin also suppressed acid secretion in response to a meal by 52% +/- 15%; postprandial gastrin response was not affected.

Oncodevelopmental and hormonal regulation of alpha 1-fetoprotein gene expression.

The main features of the oncodevelopmental biology of alpha 1-fetoprotein (AFP) are reviewed. Progress made in the molecular biology of AFP gene regulation is discussed and we present our recent data on the mechanisms of AFP suppression by glucocorticoid hormones. The relationship between AFP gene transcription and cell replication is examined, and it is suggested that the degree of methylation of the AFP gene (or of co-methylated regulatory DNA sequences) conditions its response to hormones.

Double-antibody enzyme immunoassay applied to human alpha 1-fetoprotein.

We report the development of a double-antibody system for enzyme immunoassay of human alpha 1-fetoprotein. Equilibrium and sequential saturation procedures were evaluated and compared with a similar double-antibody radioimmunoassay. With our method, 3 mug of alpha 1-fetoprotein per liter can be detected.