Dopamine D1 antagonists potentiate the durations of bar and cling catalepsy and the dorsal immobility response in rats

The effects of dopamine D1 antagonists SCH 23390 or SK&F 83566 (at SC doses of 0.00, 0.01, 0.05, and 0.1 mg/kg) were tested for 2 h on bar and cling catalepsy and the dorsal immobility response. Each of the drugs potentiated the duration of each of the three measures of immobility in a dose- and time-dependent manner. Each of the drugs had rapid but brief effects on all three response measures; the peak effect of SK&F 83566 took place at 20 min and that for SCH 23390 at 40 min for each behavior. At each effective drug dose, SCH 23390 had a greater effect than SK&F 83566 on each behavior. Dopamine D1 antagonists potentiated three different immobility responses, as do dopamine D2 antagonists.

Mechanisms of antihormone action

The mechanisms of action of two types of anti-hormones is discussed. Type I anti-hormones comprise the antiestrogen hydroxy-tamoxifen and the antiprogestin RU486, both of which promote DNA binding of the cognate receptors and, due to the activity of one of the two transcription activation functions of the estrogen and progesterone receptors, act as mixed agonist/antagonists. Evidence supporting that ICI 164,384 is also a member of the same group is presented. Type II antagonists impair DNA binding of the corresponding receptor in vitro and, in some cases, also in vivo. Ligand-mapping, an approach to identify the site of interaction of a steroid substitution within the hormone-binding domain of the receptor has been used to identify the 11 beta-pocket of the progesterone receptor and revealed that a single amino acid is responsible for the differential antagonistic effect of RU486 in man, chicken and hamster.

Sex differences in locomotor activity after acute and chronic cocaine administration

Adult, intact and gonadectomized male and female Wistar rats (n = 9) were exposed to an automated open field to assess the behavioral effects of acute cocaine administration (saline, 1.0 and 10.0 mg/kg subcutaneous). The subjects were exposed to the open field for 10 min, removed to be injected and returned to the open field for another 30 min. Three saline and two drug sessions were run in counterbalanced order. Locomotor activity in intact and castrated male rats and ovariectomized female rats decreased following injection, irrespective of the dose of cocaine. The locomotor activity of intact female rats was higher than that of any other group of subjects. It decreased during the session after saline and 1.0 mg/kg cocaine, but increased towards the end of the 30 min session after 10.0 mg/kg. Rearing measures paralleled the observations on locomotor activity. To determine the effects of chronic, home-cage, cocaine administration, five of the subjects in each group were injected with 10.0 mg/kg cocaine for 9 consecutive days. The remaining four subjects received saline injections. On day 10, all subjects were re-exposed to the open-field for 10 min, removed, injected with 10.0 mg/kg cocaine and returned to the open field for another 30 min. Chronic home cage cocaine administration produced an increase in cocaine's effects on locomotor activity and rearing in intact female rats only. However, behavioral sensitization was also observed in intact female rats who had been treated with saline for 9 consecutive days, suggesting that behavioral sensitization to cocaine in intact female rats may develop very rapidly and independent of environmental context.

Progestin receptors: isoforms and antihormone action

We present evidence that the two isoforms of A and B of the chicken (cPR) and human progesterone receptor (hPR) originate from two different mRNA populations. One of these encodes the isoforms A which originate by initiation of translation at an in-frame AUG found 127 (cPR) and 165 (hPR) codons downstream of the AUG which gives rise to the isoforms B. Two estrogen-inducible hPR promoters were identified which are responsible for the generation of these two classes of transcripts. Characterization of the cPR promoter suggested the possible existence of cell-type and isoform-specific auto-regulation of cPR transcription and provided evidence that estrogen-induction of cPR expression occurs at a post-transcriptional level. Finally, we demonstrate promoter-specific transcriptional activation by the hPR isoforms A and B, and we discuss the mechanism of action of the anti-progestin RU486.

Agonistic and antagonistic activities of RU486 on the functions of the human progesterone receptor

RU486 induced the binding to a palindromic progestin responsive element (PRE) in vitro of homo- and heterodimers of the human progesterone receptor (hPR) isoforms A and B, present in T47D breast cancer cells or in HeLa cells transiently expressing the recombinant proteins. The resulting complexes were indistinguishable from those induced with the agonist R5020 with respect to specificity, affinity and stability. Ligand exposure was a necessary prerequisite to observe PR/PRE complexes. Antagonist-induced complexes migrated more rapidly during electrophoresis than agonist-induced ones, and no 'mixed' PR/RU486-PR/R5020 complexes were observed, suggesting that the dimerization interfaces of agonist- and antagonist-bound molecules are non-compatible. The analysis of a series of deletion mutants and chimeric receptors revealed the presence of two transcription activation functions (TAFs), located in the N-terminal region A/B (TAF-1) and the hormone binding domain (TAF-2). In the presence of agonists, both TAFs were active in HeLa cells. In the presence of RU486 TAF-2 was inactive, while TAF-1 within the hPR form B/RU486 complex activated transcription from a reporter gene containing a single palindromic PRE. We consider this to be the most convincing evidence that the receptor/RU486-complex does in fact bind to PREs in vivo. No transcriptional activation was observed in the presence of RU486 from a reporter gene containing the complex MMTV-LTR PRE. In contrast to hPR form B, form A was not able to activate transcription from PRE/GRE-tk-CAT in the presence of RU486. In vivo competition between hPR/RU486 and either cPR/R5020 or the human glucocorticoid receptor/dexamethasone (hGR/Dex) complex further supported that hPR/RU486 bound in vivo to its cognate responsive element. Indeed, the observed inhibition of transcription was shown to be due to competition for the MMTV PRE, since no transcriptional interference by the hPR/RU486 was observed, and since no heterodimers were formed between hPR/RU486 and cPR/R5020 or hGR/Dex. That the ligand-free hPR, however, was unable to compete, demonstrated that ligand binding is the prerequisite for DNA binding of hPR in vivo.

Repression of the alpha-fetoprotein gene promoter by progesterone and chimeric receptors in the presence of hormones and antihormones

Using transient transfection assays, we showed that repression of the alpha-fetoprotein promoter by intact and deletion mutants of the progesterone receptor and by chimeric progesterone/glucocorticoid-estrogen receptors in the presence of their cognate hormones was closely correlated with their ability to bind to a progesterone/glucocorticoid-responsive element. This negative regulation was also observed in the presence of antihormones, providing evidence that receptor-antihormone complexes can bind to their responsive elements in vivo.

Labyrinthine and visual involvement in the dorsal immobility response of adult rats

The dorsal immobility response (DIR) is typically seen in the infants of many altricial mammalian species. Lifting the animal into the air by the nape of the neck is the primary releasing stimulus. Functionally, this response appears to facilitate carrying of the infants by the adults. When grasped by the nape and lifted into the air, adult rats will also exhibit the DIR. In this paper, the role of the labyrinths in the DIR of adult male rats was examined. Vestibular stimulation produced by vertical circular acceleration increased the duration of the DIR, while labyrinthectomy greatly diminished the DIR. In rats with intact labyrinths, visual occlusion greatly potentiated the DIR, whereas, in labyrinthectomized rats, visual occlusion had little effect. These data indicate that the vestibular system plays a major role in mediating the DIR of adult rats. The retention of the DIR into adulthood and the possible increased role of the labyrinths in the control of the adult DIR, are discussed with respect to the possible role of the DIR as an anti-predator mechanism.

An open-field activity analysis of labyrinthectomized rats

A detailed behavioral analysis was performed on rats that received bilateral labyrinthectomies. They were placed in a walled activity monitor (39 x 39 cm) that allowed the animal to move freely within the enclosure. Their behavioral activities were automatically recorded. These activities were placed into twelve different categories. The results show a lower rate of habituation for the labyrinthectomized animal as well as an overall increase in activity over all dimensions as compared to the control. This increase in behavior may be exploratory and a necessary feature in the formation of spatial maps.

Dorsal pressure differentially affects patterning of locomotor activity in rats

This study tested the generalizations that cutaneous pressure will induce immobility effecting various patterns of locomotor activity and that various intensities of pressure will effect those activities. Dorsal pressure (5 and 9 kg) resulted in immobility and suppressed various measures of horizontal and vertical locomotor activities, as well as margin and corner time, but has no effect upon various measures of stereotypy. The differential intensity of dorsal pressure was related to only measures of rearing behaviors.

Dorsal pressure potentiates the duration of tonic immobility and catalepsy in rats

This study tested the generalizations that cutaneous pressure will elicit immobility, that there is a relationship between the intensity of cutaneous pressure and the duration of immobility, and that the localization or body surfaces, particularly the upper dorsal area or the nape of the neck, is more susceptible to immobility. Immobility was measured by the duration in sec of tonic immobility, bar grasp and vertical cling behaviors or catalepsy. It was shown in the first experiment that dorsal pressure immobility can be elicited in the adult rat. The application of a 9-kg pressure elicited a significant potentiation of the duration of tonic immobility and the bar grasp catalepsy and both 5 and 9 kg of pressure potentiated the duration of vertical cling catalepsy. In the second experiment, only pressure applied to the midline of the dorsal surface at the nape of the neck significantly potentiated the duration of these measures. These results were compared with other experimentally and naturally occurring immobilities.

Effects of intrastriatal hormones on the dorsal immobility response in male rats

Previous research has shown that estradiol administered either peripherally or directly into the striatum potentiates the dorsal immobility response (DIR) in ovariectomized female rats. Male rats are even more responsive than females to intrastriatal estradiol, and furthermore respond to the effects of catecholestrogens while females do not. In order to determine whether the heightened effects of estrogens in males are due to conversion to catecholestrogens, castrated male rats were given bilateral intrastriatal implants of moxestrol, which cannot be readily converted to a catecholestrogen, and diethylstilbestrol, which can. To determine whether the effects of intrastriatal estradiol in male rats might be related to the effects of androgens on the striatum, castrated male rats were given bilateral intrastriatal implants of testosterone, which can be aromatized to estrogen, and 5 alpha-dihydrotestosterone, which cannot. The effects of each of the hormones tested were measured against those of cholesterol (an inactive control substance) and 17 beta-estradiol. In each case the DIR was measured four hours after the hormone implant. Both synthetic estrogens and 17 beta-estradiol significantly potentiated the DIR, while neither of the androgens had an effect. Thus, the effects of estradiol, synthetic estrogens and catecholestrogens on the male striatum appear to be due to the estrogenic properties of these hormones.

Effects of intrastriatal hormones on the dorsal immobility response in the rat

Previous research has shown that the dorsal immobility response (DIR) changes significantly in duration across the estrous cycle. In order to test whether gonadal steroid hormones act directly on the striatum to modulate this behavior, ovariectomized female Long-Evans hooded rats were given bilateral intrastriatal implants of 17 beta-estradiol, 2-hydroxyestradiol, progesterone, or cholesterol. These implants were made at one-week intervals, each animal receiving each treatment in a Latin square design. Four hours after each hormone implant, the animals were tested for the DIR. Only rats receiving the intrastriatal 17 beta-estradiol implant were significantly different from those receiving cholesterol, and showed greatly potentiated DIR's.

The effects of intrastriatal hormones on the dorsal immobility response in gonadectomized male and female rats

Previous research has shown that intrastriatal estradiol potentiates the dorsal immobility response in ovariectomized female rats. In order to test whether the gonadal steroid hormones act on the male striatum in the same way, gonadectomized male and female Long-Evans hooded rats were given bilateral intrastriatal implants of 17 beta-estradiol (17 beta-E2), 17-alpha-estradiol (17-alpha-E2), 2-hydroxyestradiol (2-OH-E2), 4-hydroxyestradiol (4-OH-E2), or cholesterol. Four hours after the hormone implant the dorsal immobility response (DIR) was measured. In the ovariectomized females, the DIR was significantly potentiated only by 17 beta-E2 and 17-alpha-E2. In the castrated males, the DIR was significantly potentiated by 17 beta-E2, 17-alpha-E2, 2-OH-E2, and 4-OH-E2. While the DIR durations did not differ between males and females after intrastriatal cholesterol, the males had significantly longer DIR durations after each of the other hormones. These results are discussed in terms of estradiol stereospecificity and the properties of catechol estrogens in male and female rats.

Affiliative behavior in voles: effects of morphine, naloxone, and cross-fostering

Species differences in affiliative behavior were examined in prairie and montane voles. Unfamiliar male-female pairs were placed in a test-cage for 2 hr and side-by-side huddling was recorded during the third hour. Prairie vole pairs spent a mean of 31.2 minutes in contact whereas montane voles were in contact only 1.3 minutes. In order to examine the effects of experience on affiliative differences, pups of each species were cross-fostered. Fostered prairie vole parents did not survive longer than 7 days, whereas fostered montane voles were successfully weaned; cross-fostering had no effect on their huddling behavior when tested as adults. The effects of morphine (5 and 10 mg/kg) and naloxone (5 and 10 mg/kg) on side-by-side contact were evaluated in both species. Morphine (10 mg/kg) reduced huddling duration and activity levels in prairie voles. There were no other drug effects in either species.

Effects of intracerebral estradiol on the dorsal immobility response in the rat

The effects of intracerebral implants of 17 beta estradiol and cholesterol in five brain regions were tested on the duration of the dorsal immobility response in ovariectomized female rats. The dorsal immobility response was significantly prolonged by 4-hr implants of 17 beta estradiol in the dorsal striatum and nucleus accumbens, but not in the cortex, the globus pallidus, or the substantia nigra pars compacta. These data further support previous evidence that estradiol acts directly on the striatum to affect behavior in the rat.

Steroid hormone receptors compete for factors that mediate their enhancer function

Stimulation of transcription of reporter genes by the progesterone receptor (PR) was inhibited in transfected HeLa cells by co-expressing the estrogen receptor (ER) in an ER-dose- and estrogen-dependent manner. Both the N-terminal A/B region and the hormone binding domain of ER were involved in this inhibition, which was antagonized by antiestrogens and did not appear to involve direct interaction between ER and either reporter gene or PR. ER expression also inhibited activation by the glucocorticoid receptor (GR), and both PR and GR expression inhibited activation by ER, albeit to a lower extent. Similar transcriptional interference was observed between the endogenous PR and ER present in T47D and MCF-7 breast cancer cells transfected with an ER reporter gene. Moreover, transcription of the resident estrogen-induced pS2 gene was partially inhibited by exposing MCF-7 cells to progestins or glucocorticoids. We propose that these observations reflect competition for a functionally limiting transcription factor(s).

Blood pressure during induction and termination of the dorsal immobility response

Evidence has indicated that afferent baroreceptor input may play a role in the induction of the dorsal and tonic immobility responses, which are behaviorally similar, but involve opposite posture changes upon induction (i.e., upright versus inverted, respectively). Information is lacking on the topography of the blood pressure response during periods of dorsal immobility. The blood pressure response of the adult Wistar rat during induction and termination of dorsal immobility was compared to the blood pressure response during a condition which controlled for posture change. Each animal received two control trials, ten dorsal immobility trials and then two control trials in two successive sessions four and ten days after surgery. A precise second-by-second topographical analysis of the dorsal immobility response revealed a sharp rise in blood pressure at trial onset of 18.4 mmHg, followed by a return below pretrial levels and then subsequent recovery back to pretrial levels by the tenth-trial second. This level was maintained until the last five seconds of immobility when a rapid blood pressure elevation occurred. This terminating elevation correlated highly with the observation of large movement and probably reflected motor activity that eventually culminated in escape from immobility. The vertical posture change of the control condition, on the other hand, resulted in a gradual diminution of blood pressure, which implied that the initial blood pressure elevation during initiation of the dorsal immobility response could not be accounted for simply by posture change.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of geriatric patients' functional ability to take medication

The abilities of 93 geriatric patients (inpatients and outpatients) to perform medication-taking skills were assessed. These skills included the ability to read and interpret prescription labels, open and close vials, remove tablets, and identify tablet colors. The educational level and cognitive capacity using Jacobs' Cognitive Capacity Screening Examination (CCSE) was determined. The average age was 74.3 +/- 10.1 years. Eighty-nine of our participants were male. Age and educational level did not affect functional abilities. Fewer outpatients had problems interpreting prescription label directions than did inpatients. Patients who managed their own medications were more likely to be able to read and interpret labels, remove tablets, and identify colors (p less than 0.05). Patients with CCSE scores less than 20, indicating cognitive impairment, were less likely to correctly read and interpret labels and differentiate colors than patients without impairment. Motor skills (opening/closing vials, removing tablets) were not related to cognitive status. This functional tool was easily administered and was useful in the assessment of medication-taking skills in geriatric patients.

Expression of active hormone and DNA-binding domains of the chicken progesterone receptor in E. coli

Bacterially-expressed fusion proteins containing the DNA-(region C) or hormone-binding (region E) domains of the chicken progesterone receptor (cPR) fused to the C terminus of Escherichia coli beta-galactosidase were analysed for the specificity of interaction with natural and synthetic hormone-responsive elements (HREs) and progestins, respectively. The purified fusion protein containing the progestin-binding domain bound progesterone with an apparent Kd of 1.0-1.5 nM and was specifically photocross-linked with the synthetic progestin R5020 in crude bacterial lysates. Labelling of intact bacterial cells with [3H]R5020 revealed that the majority, if not all, of the bacterially produced hormone-binding domain was active. No differences in the binding to a synthetic palindromic glucocorticoid/progestin-responsive element (GRE/PRE) were found when the bacterially produced cPR DNA-binding domain was compared in methylation interference assays with the full-length chicken progesterone receptor form A expressed in eukaryotic cells. The study of dissociation kinetics, however, revealed differences in the half-life of the complexes formed between the palindromic GRE/PRE and either the receptor form A or the fusion protein containing the cPR DNA-binding domain. DNase I protection experiments demonstrated that the bacterially produced region C of the cPR generated specific 'footprints' on the mouse mammary tumour virus long terminal repeat (MMTV-LTR) which were nearly identical to those previously reported for the rat glucocorticoid receptor.

The chicken progesterone receptor: sequence, expression and functional analysis

The complete mRNA sequence of the chicken progesterone receptor (cPR) has been determined. Expression of the cloned cDNA both in vivo and in vitro produces a protein that has the same apparent mol. wt on SDS--polyacrylamide gels as the 'natural' cPR form B (109 kd) as determined by immunoblotting and photoaffinity labelling. When expressed in HeLa or in Cos-1 cells the 'cloned' cPR displays hormone binding characteristics indistinguishable from the 'natural' receptor and, in the presence of progestins, exhibits 'tight nuclear binding'. A protein corresponding in size to the cPR form A (79 kd) could be detected by expressing in vivo and in vitro an N-terminally truncated cPR starting at methionine 128. A protein of the same apparent mol. wt results from internal initiation during in vitro translation. In contrast, such a protein was barely detectable after in vivo expression of the cPR cDNA in Cos-1 cells. These results suggest that form A is generated by an oviduct cell specific process involving either internal initiation of translation and/or proteolysis in the vicinity of methionine-128. The cPR contains two highly conserved regions C and E, a characteristic of the steroid/thyroid hormone receptor supergene family. By expression of a series of cPR deletion mutants, region E could be defined as the hormone binding domain whereas region C is indispensable for the tight nuclear association of the progestin-receptor complex. In the presence of progestins, the cloned cPR efficiently trans-activates transcription from the long terminal repeat region (LTR) of the mouse mammary tumor virus (MMTV). Deletion of the entire N-terminal region A/B or of the hormone binding domain E results in a 100-fold reduction of transcriptional activation. No stimulation of transcription can be detected when the C-terminal deletion extends into region C, indicating that this region is involved in the recognition of the hormone responsive element (HRE) of the MMTV LTR.

High-Efficiency Conversion of Pyruvate to Acetoin by Lactobacillus plantarum during pH-Controlled and Fed-Batch Fermentations

The influence of pH on the type and concentration of metabolites produced from pyruvate by Lactobacillus plantarum ATCC 8014 was examined in pH-controlled fermentors at pH values of 4.5 to 6.5. Specific growth rates, cell dry weights, and diacetyl concentrations were highest at pH 5.5, with values of 0.78 h −1 , 190 mg/liter, and 1.2 mM, respectively. While the conversion efficiency (millimoles of acetoin formed per millimoles of pyruvate utilized) was highest (94.6%) at pH 4.5, acetoin levels were similar (20 mM) between pH 4.5 and 5.5. Feeding stationary-phase cells exogenous pyruvate increased acetoin levels to 78 mM.

Effects of estrus, estrogen-progesterone priming, and vaginal stimulation on tonic immobility, dorsal immobility, and lordosis in the female rat

Three complex inhibitory responses, tonic immobility, the dorsal immobility response, and lordosis, were studied in the intact female rat during estrus and diestrus and in ovariectomized rats with estrogen-progesterone treatment or controls. In each condition, the effects of vaginal-cervical stimulation were also studied. The results of two experiments indicate that estrus and estrogen-progesterone treatment significantly potentiate lordosis and the dorsal immobility response with or without vaginal-cervical stimulation. Tonic immobility was also potentiated by estrus and estrogen-progesterone treatment, but only if vaginal-cervical stimulation was applied. Vaginal-cervical stimulation potentiated both tonic immobility and the dorsal immobility response, but not lordosis, which was already at a high level.

Morphine and naloxone effects on tonic immobility and the dorsal immobility response in the rat

Adult male Wistar rats treated with morphine sulfate (0.5, 5.0, and 10.0 mg/kg, SC) showed a dose-dependent potentiation of tonic immobility (TI) and dorsal immobility response (DIR) durations. Naloxone (4.0 mg/kg, SC) did not affect the DIR durations but reversed the potentiated morphine effects on both TI and DIR. These results suggest that although opiate receptors may be involved, mu-opiate receptor function is not essential for modulating various complex immobility responses.

Characterization of Brucella abortus strain 19 isolated from human and bovine tissues and fluids

One hundred isolates of Brucella abortus, which were recovered from bovine and human tissues or fluids, were identified as strain 19 by conventional bacteriologic methods. Each isolate was examined using a Warburg respirometer to determine oxidative rates on substrates of D- and L-alanine, L-glutamic acid, d(+)-galactose, D-ribose, and i-erythritol. These results were compared with those of repository (seed) cultures of strain 19 used for making antigens and vaccines. Except on the substrate of i-erythritol, each of the 100 isolates oxidized these substrates with rates different from the repository cultures and indistinguishable from those of field strains of B abortus. Thus, oxidatively, i-erythritol was the only substrate useful to help distinguish between strain 19 and virulent strains of B abortus biotype 1.

Epidemiology of bovine brucellosis in Mexicali Valley, Mexico: use of path analysis to refine the existing control program

This paper describes how path analysis, a quantitative analytical technique, was used to evaluate details on the epidemiology of bovine brucellosis in a discrete geographic area of Baja California Norte, Mexico. The steps involved in the analysis are discussed and details are presented for refining and improving the bovine brucellosis control program in this geographic area.