Martin Pfaffendorf

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OBJECTIVE The aim of this study was to investigate whether diabetes and hypertension cause additive effects in the responses to various vasoconstrictor and vasodilator agents, in isolated perfused kidneys obtained from streptozotocin (STZ)-diabetic Wistar-Kyoto (WKY) rats and from diabetic spontaneously hypertensive rats (SHR). METHODS SHR and WKY rats(More)
The influence of vascular endothelium on angiotensin II-induced contraction and the underlying mechanisms in the rabbit renal artery were investigated. In endothelium-intact preparations, angiotensin II (3-100 nM) caused a concentration-dependent increase in tension by maximally (Emax) 0.74 +/- 0.05 g. Removal of the endothelium significantly enhanced the(More)
Since hypertensive disease and diabetes frequently occur simultaneously there exists a requirement for animal models where both pathological entities are combined. The streptozotocin (STZ)-spontaneously hypertensive rat (STZ-SHR) and the obese Zucker rat are examples of animal models where hypertension and diabetes occur simultaneously. STZ-SHRs develop a(More)
1. The inhibitory effects of methylene blue (MB) on different types of cholinesterases and [3H]-N-methylscopolamine ([3H]-NMS) binding to muscarinic receptors were studied. 2. Human plasma from young healthy male volunteers, purified human pseudocholinesterase and purified bovine true acetylcholinesterase were incubated with acetylcholine and increasing(More)
A previous study by our group has demonstrated that the selective AT1-receptor antagonist losartan behaves as a noncompetitive antagonist in rabbit isolated renal artery (RA). In the present investigation, the influence of losartan and irbesartan on the contractile effects of angiotensin II (AII) and its degradation products angiotensin III (AIII) and(More)
The dihydropyridine calcium antagonists differ in respect to their structures as well as their pharmacological profiles. An improved vascular selectivity has been claimed for some of the newer agents (amlodipine, felodipine, isradipine, lacidipine, lercanidipine, manidipine and nicardipine), implying that these agents exert a stronger action on the(More)
T-type calcium channels may be involved in the maintenance of myogenic tone. We tested their role in isolated rat cremaster arterioles obtained after CO(2) anesthesia and decapitation. Total RNA was analyzed by RT-PCR and Southern blotting for calcium channel expression. We observed expression of voltage-operated calcium (Ca(V)) channels Ca(V)3.1 (T-type),(More)
Sympathetic neurotransmission in tissues with intact sympathetic nerve arborization is extensively dependent on calcium influx via N-type calcium-channels. It was the objective of the present study to assess and compare the claimed sympatholytic effect of the 1,4-dihydropyridine compound cilnidipine with other voltage-dependent calcium-channel (VDCC)(More)
The experimental anticancer drug cyclopentenyl cytosine (CPEC) was associated with cardiotoxicity in a phase I study. The aim of the present study was twofold; first we investigated whether the observed effects could be reproduced in in-vitro and in-vivo rat models. Second, we intended to investigate the underlying mechanism of the possible cardiotoxicity(More)