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Sexual dimorphism of blood pressure in spontaneously hypertensive rats: effects of anti-androgen treatment

The mechanisms resulting in the greater predisposition of male subjects towards hypertension were investigated in different strains of rats with genetic hypertension [spontaneously hypertensive rats of the stroke-prone strain (SHRSP) and spontaneously hypertensive rats (SHR)] and their respective normotensive controls. Blood pressure was reduced in young (9 weeks of age) hypertensive rats by (1) surgical castration, (2) treatment with the testosterone receptor antagonist cyproterone acetate (CPA), which does not elevate testosterone, or (3) with the testosterone receptor antagonist flutamide, which leads to a feedback elevation of gonadotrophic hormones and plasma testosterone. These treatments had no effect on high blood pressure in old hypertensive rats aged 25 weeks. Both androgen receptor antagonists attenuated high blood pressure development when given for the first 10 days after birth. These data clearly relate the sexual dimorphism of hypertension to testosterone produced during male brain maturation in the early phase of hypertension development. Testosterone appears not to contribute directly to the maintenance of high blood pressure in established hypertension.

Prostaglandins and their receptors

Euler’s description that seminal vesicles contain a prostate-derived hypotonic activity [1] causing various pharmacological effects initiated an intense search for the active entities, the prostaglandins. This marks the beginning of the study of paracrine hormonal regulation in tissues. Research revealed that arachidonic acid, which is cleaved from the cell membrane by phospholipases, is the precursor of the prostaglandins (on which we concentrate in this review) and of the structurally related leukotrienes and lipoxins (Fig. la).

Orthostatic Challenge during Neuroleptic Test Dose: A Possible Predictor of Short-Term Outcome

Cardiovascular measurements were used as indicators of autonomic arousal during an orthostatic challenge test without medication and after a test dose of 150 mg perazine in 20 acute schizophrenic patients. Unmedicated schizophrenics showed elevated heart rates and elevated systolic and diastolic blood pressure in comparison to healthy volunteers. After a test dose of 150 mg perazine, responders (using BPRS outcome criteria after 23 days) showed a pronounced orthostatic heart rate reaction in comparison to nonresponders. Results are discussed in relation to arousal theories and central dopaminergic activity in schizophrenia.

Sexual Dimorphism of Cardiovascular Function: The Role of Androgens

Large-scale epidemiological studies have shown that the level of blood pressure is lower in women before menopause than in men (HDFP Cooperative Group 1977; Dawber 1980; Eiff et al. 1986; Cirillo and Trevisan 1992). Likewise, the prevalence of hypertension is considerably lower in premenopausal women than in men. In women after menopause, however, blood pressure levels and the prevalence of hypertension exceed the levels in men (Cirillo and Trevisan 1992). The generally held belief for this gender discrepancy is that ovarian hormones provide protection against cardiovascular disease. However, there is increasing evidence that testosterone and its metabolite dihydrotestosterone have an important effect on blood pressure and cardiovascular control mechanisms. Animal studies have shown that blood pressure is higher in genetically hypertensive male rats of different strains (Cambotti et al. 1984; Ganten et al. 1989; Ashton and Balment 1991) and in genetically hypertensive mice (Schlager and Weibust 1967; Schlager 1968), as well as in deoxycorticosterone (DOC)-salt hypertensive rats (Share et al. 1988), in which hypertension is induced by unilateral nephrectomy followed by subcutaneous administration of the mineralocorticoid DOC and 1% NaCl in the drinking water, a form of hypertension which requires the presence of vasopressin (Crofton et al. 1979).

Development of New Immunocontraceptives-Industrial Perspective

Contraception has been practiced for thousands of years. Nevertheless, it took until the late 1950s and early 1960s before a major breakthrough in contraceptive technology was achieved by the introduction of oral hormonal contraceptives. However, we have not succeeded in the development of a non‐hormonal contraceptive that is comparable to the pill regarding its efficacy, safety, and acceptance. The immunological interference with the complex fertilization process is a very attractive target in this respect, whereby the zona pellucida, a non‐cellular surrounding of all mammalian eggs, represents a potentially ideal target. Another interesting target are sperm: either for the development of a female contraceptive or for a male contraceptive, although the latter approach does not look very promising so far. In conclusion, given the enormous impact on mankind of a growing world population and given the very individual needs for contraceptive methods of different women in one and the same country and in different cultures we should make widely available a whole set of suitable, adjusted methods of fertility control and this includes the search for an effective method of male fertility control.

Molekulare Aspekte der Behandlung der Multiplen Sklerose

Die Multiple Sklerose (MS) ist die haufigste Autoimmunerkrankung des Nervensystems und mit die Hauptursache einer neurologischen Behinderung junger Erwachsener. Pathologie, Pathophysiologie und Pathogenese der MS, die als Prototyp einer Entmarkungskrankheit angesehen wird, werden zunehmend besser verstanden.

Pharmacological and clinical-pharmacological aspects of D1 and D2 receptors

In contrast to the situation in some peripheral systems, the role of D1 receptors for clinical effects or side effects of dopaminergic therapies in Parkinson’s disease is still unclear.