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Biomedical subjects

R L Lee

Publications and source records attributed to R L Lee.

At least 37 records · Page 2Linked to original sources
PubMed1987

Alpha 2-adrenoceptor antagonists and male sexual behavior: I. Mating behavior.

Three alpha 2-adrenoceptor antagonists yohimbine, idazoxan, and imiloxan were compared by examining the effects of a single injection on male rat copulatory behavior. Dose ranges were: yohimbine: 0.25-8.0 mg/kg; idazoxan: 0.25-8.0 mg/kg; imiloxan: 12.5-50.0 mg/kg. Yohimbine and idazoxan administration produced significant increases in the number of animals copulating to ejaculation and all three drugs increased the rate of copulation as evidenced by reductions in ejaculation latency and intercopulatory interval. Only yohimbine significantly reduced mount latency and postejaculatory interval, but yohimbine and imiloxan significantly reduced intromission latency and idazoxan showed a similar trend. The highest yohimbine dose suppressed sexual activity. A time-course experiment with yohimbine (2.0 mg/kg) and idazoxan (4.0 mg/kg) showed stimulation at 75 min and a trend at 5. To further explore the arousal-stimulating capacity of the two more effective drugs, a mounting test with genital anesthetization was used. Yohimbine but not idazoxan showed marked increases in mounting at 1.0-4.0 mg/kg. Both drugs had a suppressive effect at the highest doses. These data support the involvement of alpha 2-adrenoceptors in the regulation of male sexual behavior, specifically by facilitating sexual arousal, with no effects on ejaculatory threshold, as measured by intromission frequency. Yohimbine is the most globally effective agent and it is likely that factors other than yohimbine's alpha 2-antagonism may play a role in its unique, consistent and broad behavioral effects.

Adrenergic alpha-Antagonists↗
PubMed1987

Alpha 2-adrenoceptor antagonists and male sexual behavior: II. Erectile and ejaculatory reflexes.

Three alpha 2-adrenoceptor antagonists, yohimbine, idazoxan, and imiloxan, all shown to have stimulatory effects on sexual arousal/motivation, were studied to identify their possible effects on the other two major components of male copulatory behavior: erection and ejaculation. Genital reflex ex copula tests were used in order to assess these two responses without the confounding factors of mating behavior. Dose ranges were yohimbine: 0.25-4.0 mg/kg; idazoxan: 1.0-8.0 mg/kg; and imiloxan: 12.5-50.0 mg/kg. Lower doses of two of the drugs significantly enhanced the frequency of erections, while the third (yohimbine) showed a strong trend in that direction. At higher doses, all three alpha 2-antagonists produced significant reductions in the number of rats showing penile reflexes, including both erections and ejaculations. In those rats which did show penile reflexes, higher doses of yohimbine (4.0 mg/kg) inhibited the frequency of erections, while the higher dose of idazoxan showed a trend towards such inhibition. Thus, profound, largely inhibitory effects of these agents were demonstrated at dose ranges which have been shown to enhance sexual arousal. These data indicate that within the nervous system alpha 2-adrenoceptor antagonists can modulate erectile and ejaculatory mechanisms quite independently from effects on arousal/motivation.

Adrenergic alpha-Antagonists↗
PubMed1985

Alternative systems in Malaysian drug rehabilitation: organization and control in comparative perspective.

This paper examines four drug rehabilitation systems in Malaysia from an organizational perspective. It focuses on authority structures in rehabilitation centres and their impact on rehabilitees' identities. The findings show that there are important differences between government-run and private centres in terms of administration and approach to therapy. Some policy implications are derived from a comparison of these systems.

Combined Modality Therapy↗
PubMed1981

Structure and anti-structure in the culture-bound syndromes: The Malay case.

Turner's concepts of structure and anti-structure are applied to the culture-bound syndromes to demonstrate that they are dialectical aspects of cultural reality, The Malay cases of amok, latah and possession hysteria are discussed as instances of anti-structural behaviors that dramatize role-reversals and role-enhancement. The performers of these behaviors are not subjected to the Malay code of moral conduct. The supernatural ethos in Malay culture plays an important role in shaping tolerance towards them. Although this tolerance has been gradually eroded as a result of the introduction of Western psychiatry, the anti-structural status of these syndromes has not faded away but has assumed new meanings in terms of psychopathology.

Cultural Characteristics↗
PubMed1980

The role of biotransformation in organic mercury neurotoxicity.

Although the clinical patterns of organic and inorganic mercury poisoning are very different, systemic toxicity experiments have shown that the histological changes in the kidneys and dorsal root ganglia neurones are identical with the 2 classes of compounds. It has been further suggested that the toxicity of organic mercurials is the result of biotransformation to inorganic mercury. To test this hypothesis, between 10(-7) and 10(-10) mol of mercuric chloride and methyl mercuric acetate were injected directly into the cerebrum of rats. The comparative size of lesions was estimated anatomically and by reference to blood brain barrier dysfunction. Inorganic lesions were only slightly larger than those produced by equimolar amounts of organic mercury. Consequently both organic and inorganic mercury must be regarded as neurotoxic in their own right. Conversion of organic mercury certainly occurs but is not the only mechanism by which organic mercury exerts its toxicological effect.

Animals↗
PubMed1980

Opiate receptors, endorphins and drug therapy.

A number of opioid peptides isolated from brain and peripheral tissue have been identified, and several types of opiate receptor postulated for these endogenous substances. In this study the effects of pharmacological manipulation of 5-hydroxytryptamine (5-HT) on the antinociceptive activity of morphine and two synthetic enkephalin analogus (D-ala2-leu-enkephalin and D-ala2-met-enkephalin) were investigated in mice and rats. Centrally injected 5-HT and peripheral clomipramine pretreatment potentiated both morphine and synthetic enkephalin analgesia whilst peripheral doses of cyproheptidine, lesions in the dorsal medial raphe (DMR) and reserpine pretreatment attenuated opioid analgesia. In the reserpine-pretreated group, centrally injected 5-HT restored the antinociceptive activity of morphine and D-ala2-leu-enkephalin. These results are discussed with respect to clomipramine therapy.

Analgesics↗
PubMed1980

Effect of tricyclic antidepressants on analgesic activity in laboratory animals.

A study has been made in rodents of the interactions between a range of psychotropic drugs, narcotic agonist and partial agonist analgesics, and pain. In rodents, tricyclic antidepressants do not alone reduce pain responses but, in combination with morphine or pentazocine, clomipramine enhances analgesic activity after single doses yet increases the onset and degree of tolerance to morphine on repeated injection. The tricyclic antidepressant maprotiline, in contrast, reduced both the rate of development and extent of morphine tolerance. In morphine-dependent rats, repeated injections of clomipramine or maprotiline exerted a mixed effect upon the abstinence syndrome, some behavioural signs being potentiated whilst others were suppressed. These studies suggest that combining maprotiline with morphine will improve the control of chronic pain states.

Analgesia↗
PubMed1980

The sociocultural dynamics of mass hysteria: a case study of social conflict in West Malaysia.

This discussion of an episode of mass hysteria in a Malay college in West Malaysia examines stress and conflict in relation to the interpretive process within a specific social setting. Unlike previous studies, which conceptualize mass hysteria as a cathartic response to accumulated stress, the present study treats stress as a matter of definition in a specific sociocultural context rather than as an objective given from which predictions can be made. Objections are raised to the logic of explanations that attribute mass hysteria to environmental stress. What is of concern is how meanings are assigned to events that are experienced as stressful, how participants and observers explain these events, and the consequences that follow from their interpretations.

Conflict, Psychological↗
PubMed1976

Clincal observations of sex as a reverberation of the total relationship.

In the psychiatric treatment of sexual dysfunctioning the generally accepted method has been to concentrate heavily on the intrapsychic conflicts of one or both spouses. There now is increasing evidence that treatment is sometimes more effective if the therapeutic intervention takes place directly in the interpersonal system. Such evidence has been provided by those therapists with clinical experience in marital systems who are prepared to utilize theories evolved from a multidisciplinary approach to marital problems. This paper is meant to discuss and illustrate this shift in treatment strategy as it applies to sexual dysfunctioning and deals with the function of the interplay of sex, love, and commitment through the illustrative cases.

Female↗