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H Pei

Publications and source records attributed to H Pei.

22 records · Page 2Linked to original sources
PubMed1991

Effects of alpha adrenergic blockade during stellate ganglion stimulation on arrhythmias induced by acute myocardial ischemia in pigs.

The effects of alpha-adrenergic receptor blockade during stellate ganglion stimulation on arrhythmias induced by repeated coronary artery occlusion in pigs under spontaneous breathing were studied. Prazosin, alpha 1-receptor blocker, did not have any effect on the early ischemic dysrhythmia. Yohimbine, which selectively blocks alpha 2-receptor, significantly increased the number of premature ventricular complexes (19 +/- 3----32 +/- 2 PVC; P less than 0.01), but produced no effects on the percentage of appearance of ventricular fibrillation (VF) and ventricular tachycardia (VT). However, nonselective alpha-receptor blocker phentolamine significantly reduced the number of premature ventricular complexes (30.5 +/- 4.5----11 +/- 3 PVC; P less than 0.05), but did not affect the frequency of occurrence of VF and VT. The above results show that alpha-adrenergic mechanisms do not play any important role in the genesis of arrhythmias during ischemia in the pig model.

Adrenergic alpha-Antagonists↗
PubMed1990

[Effects of submarine engine room steady noise on the compound action potential tuning curves and its relation to cochlear pathology in guinea pigs].

Compound Action Potential Tuning Curves (CAP-TC) for tone pip of 2k, 4 kHz were examined in 8 guinea pigs before and after exposure to noise with main energy centered in the range of 0.25-4.0 kHz. CAP-TC was measured with the pure tone simultaneous masking profiles. AP was evoked by tone pip with an intensity of 10 dB above threshold. Masker level producing 40% reduction in AP amplitude was used. Relations between changes in CAP-TC and AP threshold shifts and the pathology of the stereocilia of hair cells were evaluated by surface preparation and SEM observation in 13 ears. After noise exposure, animals with damaged stereocilia showed AP threshold shift of 20-50 dB, deteriorations of CAP-TC, decrease of Q10 dB value, threshold shift of characteristic frequencies (CF) and displacement of CF towards higher frequencies. It showed that stereocilia damage may affect the susceptibility and frequency selectivity of the cochlea. We consider the CAP-TC may be an useful and sensitive index for detecting physiological and pathological conditions of the cochlea.

Animals↗