eledoisin and Hypertension

1. Renal prostaglandins act primarily as local hormones, having their effects at, or near to, sites of synthesis. PGE2 is a major determinant of renal vascular reactivity; it opposes the vasoconstrictor and natriuretic actions of pressor hormones and brakes the release of noradrenaline from adrenergic nerves. In the unanaesthetized rabbit prolonged inhibition of prostaglandin synthesis results in hypertension. In the rat, however, renal prostaglandins augment pressor stimuli. 2. Basal efflux of renal prostaglandins is positively correlated with blood flow to the inner cortex and medulla. Those stimuli which increase renal medullary blood flow do so primarily by activating prostaglandin synthetase. 3. Kinins increase prostaglandin synthesis which action modifies the renal effects of kinins. Thus, one or more renal prostaglandins contribute to the renal vasodilator action of bradykinin and mediate its effect on excretion of water as well as possibly attenuating the natriuretic action of the polypeptide. Kinins in addition to stimulating prostaglandin synthesis may determine the principal product of synthetase by regulating the enzyme PGE 9-ketoreductase, which converts PGE to PGF. The coupling of these systems within the kidney appears unique--prostaglandins mediate some of the actions of kinins and modulate others, whereas they depend on the intrarenal generation of kinins to set their level and type of activity.

Topics: Animals; Bradykinin; Eledoisin; Hypertension; Indomethacin; Kallikreins; Kidney; Kinins; Models, Biological; Norepinephrine; Prostaglandin-Endoperoxide Synthases; Prostaglandins; Regional Blood Flow; Sodium; Species Specificity; Vasomotor System

Topics: Blood Pressure; Clinical Trials as Topic; Eledoisin; Humans; Hypertension

Topics: Clinical Trials as Topic; Eledoisin; Heart; Humans; Hypertension

Topics: Clinical Trials as Topic; Eledoisin; Humans; Hypertension; Respiration

A shortened and modified eledoisin-hexapeptide sequence (Lys-Phe-Ile-Gly-Leu-MetNH2) was tested for their action on avoidance learning and blood pressure of rats with spontaneous hypertension (SH-rats) and intact Wistar rats. Both groups were 10, 14, and 26 weeks of age. Disorders of avoidance learning and elevation of blood pressure were likely to aggravate along with growing age of SH-rat. The used eledoisin-hexapeptide sequence is related to the essential C-terminal pentapeptide sequence of Substance P (SP). After injection of the used hexapeptide at doses of 250 microgram/kg intraperitoneally disorders in avoidance learning were completely eliminated from ten-week SH-rats or conditionally for SH-rats aged 14 and 26 weeks. Elevated blood pressure in SH-rats aged 26 weeks was reduced by the hexapeptide from 220 Torr to approximately 190 Torr. Blood pressure in SH-rats aged 14 weeks, originally about 180 Torr, was almost unaffected by the hexapeptide. Blood pressure went up from about 150 Torr to 190 in ten-week-old Sh-rats. A hypothesis was made about the mode of action of Substance P and related peptides.

Topics: Animals; Avoidance Learning; Blood Pressure; Eledoisin; Hypertension; Rats; Rats, Inbred Strains

Topics: Adult; Blood Pressure; Catecholamines; Eledoisin; Fatty Acids, Nonesterified; Female; Humans; Hypertension; Male; Middle Aged

Topics: Arteriosclerosis; Eledoisin; Hemodynamics; Humans; Hypertension; Hypertension, Renal

Topics: Amines; Animals; Anura; Basidiomycota; Blood Pressure Determination; Cats; Chickens; Columbidae; Dogs; Eledoisin; Female; Guinea Pigs; Hypertension; Male; Muscle, Smooth; Peptides; Rats; Salivary Glands; Uterus

Topics: Adrenal Medulla; Adult; Blood Pressure; Eledoisin; Humans; Hypertension; Sympathetic Nervous System; Tachyphylaxis

Topics: Biomedical Research; Blood Pressure; Blood Pressure Determination; Drug Therapy; Eledoisin; Geriatrics; Heart; Heart Rate; Hemodynamics; Hypertension; Pharmacology; Pulse

Topics: Bradykinin; Cerebrovascular Disorders; Eledoisin; Humans; Hypertension; Intermittent Claudication; Kallidin; Kinins; Peptides; Trypsin