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The role of hemodynamic and biochemical changes due to diabetes in the mechanical and morphological properties of mesenteric small arteries of rats has been studied using an in situ model. Diabetes was induced in seven male rats by the administration of 70 mg/kg of streptozotocin in citrate buffer. Results indicate that the mesenteric small arteries show eutrophic outward modeling and have elevated circumferential wall stresses. It is speculated that the advanced glycosylation of proteins involved in normal arterial control interferes with the hypertrophic response.

The circadian and ultradian profiles of systemic hemodynamic parameters in spontaneous hypertension can be investigated by recording cardiac output (CO) and mean arterial pressure (MAP) on a beat-to-beat basis for 24 hours in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). It was found that values of CO were high during the dark and low during the light period. The highest total peripheral resistance was recorded during the light period. It was concluded that dynamic control of CO does not change in SHR. There is a frequency dependent element in autonomic effects on CO.

Spontaneous fluctuations in systematic arterial pressure noticeably exhibit slow oscillations that originate in regionally specific myogenic oscillatory mechanisms contributing to flow resistance. In conscious resting rats. beat-to-beat fluctuations in systematic mean arterial pressure (MAP) were compared with cardiac output and blood-flow. MAP was also measured in the mesenteric, hindquarter and renal vasculature. Myogenic mechanisms seem to regulate mesenteric and renal blood flow while blood flow in the hindquarters seems to be controlled autonomically.

Three angiotensin II antagonists and radioligand studies were used to study and characterize an angiotensin receptor from chick chorioallantoic membrane. Results reveal a novel type of angiotensin receptor distinct from the mammalianAT1 and AT2 receptors. Characterization of the receptor reveal that it containsbinding sitess numbering 1,190 fentomoles per milligram receptor. Further, bnding of angiotensin II to the receptor promoted a CGP 4112A-blocked neovascularization in pre- and post capillary vessels.