Search PubMed⌕ Search

Biomedical subjects

C Kohler

Publications and source records attributed to C Kohler.

At least 73 records · Page 4Linked to original sources
PubMed1980

A review of the effects of fenbufen and a metabolite, biphenylacetic acid, on platelet biochemistry and function.

gamma-Oxo(1,1'-biphenyl)-4-butanoic acid (fenbufen) and biphenylacetic acid have effects on platelets similar to other non-steroidal antiinflammatory agents. In vitro biphenylacetic acid (BPAA), a metabolite of fenbufen, is more potent than fenbufen and in vivo metabolism of fenbufen to BPAA is probably required for activity. The arachidonate-thromboxane system appears to play a critical role in explaining a major part of the mechanism of action of these agents on platelets and other systems. Fenbufen, however, also inhibits collagen-induced platelet aggregation without requiring metabolic conversion to BPAA. The mechanism for this inhibition appears to be independent of the arachidonate-thromboxane system, as well as unrelated to serotonin release or inhibition of phosphodiesterase activity. The effects of fenbufen and BPAA on platelet biochemistry and function suggest their utility as clinical anti-thrombotic agents. This is further supported by the absence of any thrombocytopenia or bleeding tendency in animals and man.

Animals↗
PubMed1977

The effect of guanethidine and hydrochlorothiazide on blood pressure and vascular tyrosine hydroxylase activity in the spontaneously hypertensive rat.

The present study examined the effects of antihypertensive drugs (hydrochlorothiazide and guanethidine) on blood pressure and tyrosine hydroxylase (TH) activity in the spontaneously hypertensive rat (SHR). Hydrochlorothiazide (50 mg/kg X 4 days) lowered blood pressure in the SHR to a degree equivalent to that produced by reserpine (0.3 mg/kg X 3 days). However, while reserpine increased vascular and adrenal TH activity, hydrochlorothiazide had no effect. Guanethidine (30 mg/kg X 2 days) reduced blood pressure in the SHR and also depleted cardiac, vascular and adrenal gland catecholamines; However, guanethidine administration did not increase TH activity in the mesenteric vasculature or adrenal glands. These studies indicate that at equieffective blood pressure lowering doses, different antihypertensive drugs have different effects on TH activity in the SHR. Neither blood pressure reduction nor catecholamine depletion in peripheral tissues are sufficient prerequisties for increasing TH activity. The data support the suggestion, however, that amine depletion in the central nervous system or ganglia may be an important factor in the regulation of TH.

Adrenal Glands↗
PubMed1975

Sex hormones and tyrosine hydroxylase activity in vascular and adrenal tissue.

Vascular tyrosine hydroxylase (TH) activity did not appear to be affected by the sex hormones. There were no differences in enzyme activity in the mesenteric artery or vein taken from male and female normotensive or spontaneously hypertensive rats. Castration of either male or female rats did not alter mesenteric artery or vein TH activity, and the administration of estradiol, progesterone, or testosterone also had no effect on vascular TH activity. However, the sex hormones did alter activity in other tissues. Estradiol and progesterone administration to intact female rats increased adrenal TH activity, whereas castration of the male rat decreased it. Although the sex hormones were not important regulators of TH in blood vessels, vascular TH activity did appear to be under some hormonal regulation since hypophysectomy decreased mesenteric artery enzyme activity. Hypophysectomy studies also indicated that adrenal TH activity was under some hormonal regulation.

Adrenal Glands↗
PubMed1975

[Mongolism: an encephalopathy "not like others"].

Considering ancient and new aspects to Langdon Down's disease, the author points out: the varieties of evolution, due to associate physical and sensorial defects and peculiarly to the differences of intellectual level and ego structuration. They are under dependence of social and familial factors. A demonstration is given in Lyon by a sheltered workshop where mongolian adults have found good possibilities. Sexual and sentimental life is a problem of great difficulties connected with conscient and inconscient reactions of normal adult (parents and "educateurs").

Adolescent↗
PubMed1975

Antihypertensive drugs and catecholamine metabolism: effects of reserpine and hydralazine on tyrosine hydroxylase activity and norepinephrine concentrations in the spontaneously hypertensive rat.

The antihypertensive drugs, reserpine and hydralazine, produce different effects on tyrosine hydroxylase activity and norepinephrine levels in blood vessels and other tissues of the spontaneously hypertensive rat at doses which cause an equivalent reduction in blood pressure. Reserpine administration is associated with increased tyrosine hydroxylase activity in the mesenteric artery, mesenteric vein and adrenal, but the vasculature appears more sensitive to the effects of reserpine than the adrenal. This increase in tyrosine hydroxylase activity can be related to catecholamine depletion in the mesenteric artery, mesenteric vein and adrenal. Since chlorisondamine, a ganglionic blocking agent, diminished the ability of reserpine to increase tyrosine hydroxylase activity in the mesenteric artery and adrenal, it is likely that increased nerve activity is involved in regulation of the enzyme in both tissues. Hydralazine neither alters tyrosine hydroxylase activity in arteries or veins, nor depletes catecholamine levels in these tissues. In the adrenal, hydralazine increases tyrosine hydroxylase activity independently of any change in catecholamine levels. It would appear that changes in tyrosine hydroxylase activity produced by antihypertensive drugs are organ dependent and may involve both neuronal activity and amine depletion.

Adrenal Glands↗