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Biomedical subjects

D L Rowland

Publications and source records attributed to D L Rowland.

At least 37 records · Page 2Linked to original sources
PubMed1996

Genital and psychoaffective response to erotic stimulation in sexually functional and dysfunctional men.

To understand the sexual response patterns of men with premature ejaculation and erectile dysfunction, the authors compared genital and affective responses of sexually functional and dysfunctional men with 3 types of sexual stimulation: an erotic video, penile vibrotactile stimulation, and a combination of both. Genital response differed across both groups and stimulus conditions, with an interactive effect indicating that groups showed different response patterns depending on the stimulation. Affective responses also differed across groups and interacted with stimulus conditions. The combination genital and affective response was superior to either alone in distinguishing men with no sexual problems from those with erectile or ejaculatory problems (or both). These factors were particularly useful in discriminating men with premature ejaculation from those with combined premature ejaculation and erectile dysfunction.

Adult↗
PubMed1996

Clomipramine and sexual function in men with premature ejaculation and controls.

PURPOSE: We determined whether clomipramine taken as needed increases ejaculation latency in men with premature ejaculation and controls. MATERIALS AND METHODS: The study included 8 patients with primary premature ejaculation, 6 with premature ejaculation and erectile dysfunction, and 8 controls. A prospective, double-blind, placebo controlled, crossover design was used that included 2, 3-week periods with clomipramine and placebo. During treatment phases subjects took either 25 mg. clomipramine or placebo as needed, that is 12 to 24 hours before anticipated sexual activity (coitus or masturbation). Subjects also visited the laboratory during these phases for evaluation of sexual response using visual erotic stimulation with and without vibration to the penis. Daily logs of sexual activities were maintained during treatment phases. RESULTS: Clomipramine significantly increased the latency to ejaculation during sexual activity (coitus or masturbation) from approximately 2 to 8 minutes in men with primary premature ejaculation. There were no significant effects in controls and men with premature ejaculation plus erectile dysfunction. Laboratory assessment indicated that men with primary premature ejaculation were better able to control ejaculatory response with clomipramine therapy. In these men clomipramine also resulted in increased satisfaction with sex life and relationship. Clomipramine inhibited nocturnal penile tumescence in all subjects. CONCLUSIONS: Clomipramine (25 mg. as needed) effectively increases ejaculatory latency in men with primary premature ejaculation, while treatment is not effective in those with premature ejaculation and erectile dysfunction.

Adult↗
PubMed1995

Plasma testosterone in fetal rats and their mothers on day 19 of gestation.

Plasma testosterone levels were higher in pooled samples from male fetuses than from female fetuses on day 19 of pregnancy. Plasma testosterone from female fetuses with males located caudally in the uterus was higher than from females that lacked such males. Testosterone level of both male and female fetuses was correlated with maternal testosterone. No correlation was found between maternal testosterone and number of males in the litter, male-to-female ratio, or litter size. These results corroborate earlier findings of a sex difference in plasma testosterone levels on fetal day 19 in rats, and provide support for the hypothesis that female rats receive androgens from males located caudally in the uterus. No evidence was found that testosterone of pregnant females is affected by the sex ratio or size of her litter.

Androgens↗
PubMed1995

Effect of constant light on parturition and postpartum reproduction in the rat.

Light-dark (LD) cyclicity contributes to a number of reproductive events in the rat, including estrus cyclicity, and the timing of parturition and postpartum estrus. Constant light (LL) disrupts the female's cyclicity, and fertility is typically diminished. To ascertain whether constant light similarly diminishes the fertility of postpartum females, LL and LD animals were compared over three successive pregnancies on several reproductive measures including parturition, postpartum estrus and spontaneous ovulation, the timing of estrus relative to parturition, and the number, body weights, and viability of offspring. While the 24 h pattern of parturition differed for LL and LD groups, postpartum estrus and ovulation occurred reliably in both groups. The LD group showed greater variation in the birth-estrus interval, the result of a delayed estrus in those females giving birth late in the light phase. The likelihood of spontaneous ovulation and overall successful reproduction was high for both groups. Thus, unlike the cycling female, the fertility of the postpartum female is relatively unaffected by constant light. As such, these findings suggest that LD cyclicity is not critical for postpartum ovulation and estrus.

Animals↗
PubMed1995

Understanding and diagnosing sexual dysfunction: recent progress through psychophysiological and psychophysical methods.

The psychophysiological method has been applied to the study of human sexual response for well over three decades. The value of this method in providing an objective, integrated approach to the understanding of sexual response, and more specifically sexual dysfunction, is presented. Selected results from recent studies using this methodology illustrate the complex relationships that emerge among cognitive, affective, and physiological components of the sexual response. In addition, data from a systematic study of the use of psychophysiological procedures as an aid in differential diagnosis are given as evidence that this methodology offers a further strategy for assessing problems such as erectile dysfunction and premature ejaculation. Finally, recent findings utilizing sensory psychophysical procedures which relate subjective penile thresholds to sexual response and dysfunction are reviewed. Such procedures also study the interaction of physical/physiological systems with psychological events, and as such may be considered relevant to understanding the relationship between psychological aspects of sexual response.

Female↗
PubMed1995

A preliminary investigation of affective and cognitive response to erotic stimulation in men before and after sex therapy.

Affective and cognitive responses to erotic stimulation were studied in sexually dysfunctional men before and after treatment in a sex therapy program. A comparison group of functional men was studied over the same time interval. A pool of 34 Likert-scaled items assessing various cognitions, affects, and perceptions was administered during baseline and following two erotic audiotapes and a self-generated sexual fantasy. To focus on global response patterns rather than individual item responses, five aggregate indices (sexual arousal, physicality, sensuality, negative affect, positive affect) were derived using a strategy that combined face-validity and reliability analysis. Cluster analysis was employed as an auxiliary technique to confirm the coherence of these groupings. All five indices differentiated dysfunctional men from controls, and further, three indices (physicality, sensuality, sexual arousal) showed significant variation across types of erotic stimulation. Correlations among the five indices, as well as with penile response, revealed two trends that differentiated dysfunctional men from controls during the pretest, but that diminished following sex therapy in the dysfunctional men. Future investigations might further rely on multiple-item indices as described here. Such measures may provide a more integrated view of sexual response in the laboratory and lead to greater understanding of affective and perceptual differences between functional and dysfunctional men.

Adult↗
PubMed1994

Males located caudally in the uterus affect sexual behavior of male rats in adulthood.

It has been suggested that the sexual differentiation of female rats is affected by androgens from male fetuses in the uterine horn (intra-uterine position phenomenon). Effects of adjacent males, as well as of males located caudally in the uterus have been reported. The present study investigated whether male rats, like females, are affected by the presence of either caudal or adjacent male littermates. When tested in adulthood for sexual behavior, males that had male fetuses located caudally in the uterine horn showed shorter latencies to the first mount or intromission and shorter latencies to ejaculation, and exhibited more mounts and intromissions per minute than males that lacked caudal male siblings in the uterus. The presence of adjacent males did not significantly affect the parameters studied in this experiment.

Animals↗
PubMed1994

The use of vibrotactile stimulation for determining sexual potency in the laboratory in men with erectile problems: methodological considerations.

Vibrotactile stimulation, when used in combination with visual sexual stimulation, has been shown to enhance erectile response in sexually functional men. The present study attempted to describe a diagnostic methodology, including the development and application of a new mini-vibrator, that might enhance penile response in men with erection problems. Tests on 78 men with either erectile dysfunction (ED), or a combination of erectile dysfunction and premature ejaculation (ED+PE), showed that vibratory stimulation together with an erotic video (EV+VT), produced greater penile response than the erotic video alone (EV). The new mini-vibrator was more effective than a previously used model, and produced clinically significant increases in erectile response in ED+PE men. In addition, the enhancing effect of the combined stimulation on self-reported penile response was greater when it followed EV than when it preceded it. The use of vibrotactile stimulation and visual sexual stimulation together may therefore assist in determining the potential sexual potency of men experiencing erection problems during the process of differential diagnosis.

Ejaculation↗
PubMed1993

Aging and sexual function in men.

Sexual function, and in particular erectile capacity, declines with age in men. The present study attempted to identify possible sensory/neural and autonomic factors related to this decline. Data on self-reported sexual activity and functioning, as well as erectile response to visual erotic stimulation, were gathered from 39 healthy, sexually functional men ranging in age from 21 to 82. In addition, four parameters of putative significance to sexual functioning were measured: penile electrical and vibrotactile thresholds, pudendal somatosensory evoked potentials, penile autonomic response to ischemia, and blood testosterone. Results indicated significant age-related decreases in self-reported frequency of sexual activity and in erectile response to erotica. Furthermore, penile sensitivity, response to penile ischemia, and somatosensory evoked potentials showed age-related changes. In contrast, self-reported erectile capacity, ratings of overall sex life, and levels of testosterone did not change over age groups. These findings suggest that decreasing erectile capacity in aging men may be related to decreasing sensory/neural and autonomic functioning, but they also indicate that factors other than the frequency of and potency for sexual response are important to the overall rating of sex life.

Adult↗
PubMed1993

Penile sensitivity in men with premature ejaculation and erectile dysfunction.

Previous research indicates that penile sensitivity is typically lower in men with erectile dysfunction than in age-matched controls. On the assumption that sensitivity might be greater in men with short ejaculation latency (premature ejaculation), the present research investigated penile threshold (sensitivity) to vibrotactile stimulation in men with premature ejaculation, erectile dysfunction, or a combination of the two. Premature ejaculators showed thresholds commensurate with controls, while men with erectile dysfunction, or combined erectile dysfunction and premature ejaculation, showed significantly elevated thresholds. Although premature ejaculators did not show penile hypersensitivity, there was a significant correlation in this group between ejaculation latency and threshold. Overall, these findings argue against a primary role for penile sensitivity in ejaculation latency, and suggest that other somatic factors or cognitive factors may play the more critical role in premature ejaculation.

Adult↗
PubMed1992

New device for penile vibrotactile stimulation: description and preliminary results.

A small, lightweight mini-vibrator for measuring penile sensitivity is described. Data on subjective thresholds to vibrotactile stimulation were collected from sexually functional and dysfunctional men during both flaccid and tumescent penile states. Two sites, the dorsal and ventral surfaces of the glans penis, were stimulated. Results indicated a significant correlation between thresholds obtained with the mini-vibrator and those obtained with another stimulating device. In addition, the patterns of sensitivity in the flaccid and in the tumescent penis were similar to those found in previously studied samples of sexually functional and dysfunctional men. This device has advantages over other vibrators in that it can be attached directly to the penis and does not lose contact with the penile surface during tumescence.

Erectile Dysfunction↗
PubMed1992

Vibrotactile stimulation enhances sexual response in sexually functional men: a study using concomitant measures of erection.

The role of vibrotactile stimulation on the penis in producing erection was investigated in 34 sexually functional men. Subjects were presented with three stimulus segments: erotic video (VID); vibrotactile stimulation (VT) applied to the underside of the penis; and combined vibrotactile and erotic video stimulation (VID+VT). Maximum erectile response was recorded to each stimulus using both an erectiometer and a Barlow strain gauge. Self-reported sexual arousal and affective response to each stimulus segment were also obtained. Results indicated significant variation in erectile response and self-reported arousal over the stimulus segments. Erectile response was lowest to VT alone and highest to VID+VT for both erectile measures, although the pattern of change across stimuli was different for each measure. Self-reported sexual arousal was consistent with erectile measures, but the difference between VID and VID+VT was not statistically significant. VT stimulation alone was perceived as somewhat unpleasant; both VID and VID+VT were perceived as more pleasant than VT, but VID and VID+VT did not differ significantly from each other. This study demonstrates that, while not perceived as more pleasurable or arousing, VT stimulation on the penis combined with erotic video stimulation augments erectile response in functional men in a controlled laboratory situation. The possible use of this methodology for the improved study of men with sexual dysfunctions is discussed.

Adult↗
PubMed1991

Psychophysiological and endocrine responses to sexual arousal in women.

The unexplored possibility that a sexually induced endocrine response might prime further sexual arousal in women guided the current investigation. Healthy, premenopausal, heterosexual women in the follicular phase of their menstrual cycle were randomly assigned to either an experimental or a control group. The experimental group was exposed to a sexually explicit videotape, while the control group saw a nonerotic videotape. Ninety minutes later both groups saw a sexually explicit videotape. Vaginal vasocongestion and hormones (cortisol, prolactin, luteinizing hormone, testosterone) were measured continuously and subjective responses were sampled at 20-min intervals. Compared to controls, experimental subjects showed a greater amplitude and longer duration vaginal response to the second videotape. Subjective measures showed greater sexual response to the second erotic videotape compared to the first, an effect that was not mediated by the hormones measured here. Prolactin decreased significantly across the session for both groups, and several behavioral and affective responses were significantly correlated with hormonal levels. Commonalities and divergence with results of prior research point to the complexity and subtlety of endocrine interactions with sexual response as well as likely sex differences in hormone-behavioral interactions.

Adult↗
PubMed1991

Self-reported and genital arousal changes in sexually dysfunctional men following a sex therapy program.

This investigation examined the question of whether differences in psychophysiological and self-reported sexual response between sexually dysfunctional men and sexually functional men are reduced following treatment in a sex therapy program. Patterns of sexual responding before and after treatment in nine men with erectile difficulties and/or low sexual desire were compared with those of nine age-matched controls tested at the same intervals. Results indicated: (1) increased genital and self-reported response during the post-test in dysfunctional men but not in controls; (2) conditions eliciting performance demand produced less inhibition during the post-test in dysfunctional men; and (3) moderate correlations in dysfunctional men between clinically-assessed improvement in sexual functioning and actual changes in penile and self-reported arousal from the first to the second laboratory session. The implications of these data for the understanding of variables responsible for improved sexual functioning, and therefore, to clinical assessment and therapy, are discussed. Possible cognitive strategies are provided to account for discrepancies in self-reported and physical sexual arousal in dysfunctional subjects, and the efficacy and limitations of using psychophysiological methods in studying sexual response in dysfunctional men are suggested.

Adult↗
PubMed1991

Changes in penile sensitivity following papaverine-induced erection in sexually functional and dysfunctional men.

To understand more clearly the role of penile sensitivity in sexual functioning, changes in penile thresholds resulting from papaverine-induced tumescence were studied in men who were either sexually functional or suffering from erectile dysfunction. Variable vibratory tactile stimulation was applied to 2 different sites, the base and tip of the underside of the penis. With standard psychophysical methodology, subjective thresholds were determined from a minimum of 5 threshold crossings. Results indicated a significant elevation in threshold after intracavernous papaverine injection, even though only partial erection was induced in most subjects. Men with erectile dysfunction had higher thresholds than control subjects but no difference in sensitivity was found between the base and tip of the penis. These findings indicate that low penile sensitivity is characteristic of some, although not all, men experiencing erectile problems and that this sensitivity is even lower during tumescence.

Adult↗
PubMed1991

Effect of cold exposure on the hypothalamic release of thyrotropin-releasing hormone and catecholamines.

The effects of cold exposure on the release of thyrotropin-releasing hormone (TRH) and catecholamines as estimated by push-pull perfusion of the mediobasal hypothalamus were studied. Before cold exposure, the male rats had been kept at room temperature or at 30 degrees C for 3 weeks. Transfer to 4 degrees C increased plasma levels of thyroid-stimulating hormone (TSH), but this cold-induced TSH response was more pronounced in animals which had been acclimatized to 30 degrees C. Exposure to 4 degrees C also increased plasma thyroid hormone levels, but had no effect on plasma prolactin. The hypothalamic content of TRH and dopamine remained similar after transfer to 4 degrees C, but after 6 h of cold, the content of noradrenaline and adrenaline had increased 1.6-fold and 3-fold, respectively. In vivo hypothalamic release of TRH, adrenaline and dopamine remained similar during a 2-hour period in control rats kept at room temperature or 30 degrees C. The hypothalamic release of TRH, dopamine and adrenaline did not change in rats transferred from room temperature to 4 degrees C. The amount of dopamine and adrenaline in push-pull perfusate also remained similar in rats acclimatized to 30 degrees C after transfer to low temperatures. However, in these rats kept at 30 degrees C for 3 weeks, exposure to 4 degrees C increased TRH release in perfusate from the mediobasal hypothalamus in the first 15 min of cold exposure (2-fold increase). Thus, exposure to cold stimulates the hypothalamo-pituitary-thyroid axis and increases the hypothalamic release of TRH in rats which had been acclimatized to 30 degrees C.

Animals↗