Lp(a) may contribute to the increased prevalence of atherosclerotic disease in diabetic patients and patients with chronic renal failure, especially in IDDM patients whose lipoprotein pattern was not different from that of the control group.

I In order to discover whether the changes in reactivity are related to the primary cause of hypertension in spontaneously hypertensive rats (SHR) 3 Dose-response curves to Ca2+ of depolarized SHR and NW fundus strips were obtained and the effect of diazoxide on Ca2+ contractions was observed. The contractile action of Ca2+ in depolarized preparations was enhanced in both male and female SHR strips. The effect of diazoxide was more marked in SHR strips than in NW fundus strips. 4 SHR fundus smooth muscle shows the same modification of reactivity to Ba2 , Sr2 , Ca2+ and diazoxide that was previously described in arterial smooth muscle. This indicates that the cellular modification responsible for the increase of vascular tonus in SHR is not an adaptive reaction to high blood pressure. The differences between female SHR and male SHR responses are not unexpected, considering the natural evolution of hypertension in Okamoto rats which is milder in the female.

Threir molecules derived Trom Nocardia nptica bacteria. NDCM, NWSMP. and PG. have been shown to express immunomodulating properties. The present study was aimed at assessing the effects of these derivatives on natural killer (NK) activity. Two experimental protocols were adopted, consisting of incubating whole or Percoll fractionated NK eells in vitro with those substances, and ihe other in which the dorivaiives were administered in vivo to mice and the aetivity assessed later. Incubalion of spleen cells in vitro with NWSMP or its precursor NDCM promoted NK activity. This effect could be observed after only 2 h ofincubation and continued until day 2. Percoll fractions I 3. which contain most of the NK activity, were enhanced to a similar extent. Band 4. which is usually devoid of such activity, remained unresponsive even after contact with the ,V. opaca derivatives. PG was practically IncfTcctivc upon all the subsets. The results of experiments in vivo correlated wilh those obtained in vitro in that NWSMP and NDCM, but not PG. promoted NK activity. Bands 1-3 were similarly enhanced, the effect was observed afler short treatment times, and could be partially cancelled by the concomitant administration of anti-interferon antibodies (anti-IFN Ab). All these Hndings suggest that the promotingefTeetsof/V. o/rucwderivatives are mediated through alpha beta IFN. In contrast to the results observed on spleen NK cells, NK cells from the peritoneum displayed susceptibility mainly to PG. and much less to NWSMP or NDCM. The administration of PG to mice in vivo had a particularly marked promoting efTect upon the cytotoxic aciivity of peritoneal cells. One logical explanation for the difTerence observed between PG and NWSMP or NDCM may be related to the specific IFN inducing properties of these compounds as well as to the different responsiveness of ihe NK cells present in the spleen and peritoneal cavity.

No abstract

1.Injections of antagonists of angiotensin I1 into the cerebral ventricles of normotensive and spontaneously hypertensive rats were performed in order to assess the role of the isorenin-angiotensin system in the brain.2. No hypotensive effect was obtained in either normotensive or hypertensive rats, suggesting that intracranial isoangiotensin has little role in the pathogenesis of spontaneous hypertension in the rat.Key words : angiotensin antagonist, central blood pressure regulation, intrinsic brain isorenin-angiotensin system, spontaneously hypertensive rats.