Effects of long-term consumption of sewage solids on reproductive performance and serum progesterone and estradiol-17beta in mature fine-wool ewes

Eighty-four mature fine-wool ewes were randomly allotted to one of three dietary treatments to examine the influence of dietary sewage solids on reproductive performance. Treatments were a basal diet or basal plus either 3.5% cottonseed meal (CSM) or 7% sewage solids. Serum progesterone and estradiol-17beta measured in blood samples collected through an estrous cycle just before the breeding season of the first and second years were not adversely influenced by sewage feeding. Progesterone concentrations quantified in weekly blood samples collected during gestation and lactation of both years did not differ (P>0.10) among treatments. During the first lambing season, lambing data showed that ewes consuming CSM produced slightly more lambs per ewe exposed (P<0.10) than either basal- or sewage-fed ewes. During the second breeding season, midventral laparotomies revealed that ovaries from ewes receiving CSM contained more (P<0.10) corpora lutea than did those from either basal- or sewage-fed animals. However, at the end of the second lambing season, no differences (P>0.10) among treatments in the number of lambs born or weaned were observed. A third year's lambing data also revealed no difference (P>0.10) among treatments for lambing rates. These data indicate that prolonged consumption of a diet containing 7% sewage solids has little, if any, detrimental effect on reproductive performance of mature fine-wool ewes.     

The sequestration of Ca2+ by mitochondria in rat heart cells

Rat heart ventricular cells, purified by Percoll density gradient centrifugation, were incubated in the presence of 1.3 mM CaCl2. After 20 min incubation, samples of the cells were lysed in medium containing 0.3 mM digitonin, ruthenium red and EGTA, and a mitochondrial fraction was isolated at intervals thereafter. Extrapolation of the mitochondrial 45Ca2+ contents to zero time enabled the endogenous 45Ca2+ to be estimated at the time of cell lysis. The lysis conditions yielded essentially complete release of lactate dehydrogenase from the cells, but caused negligible damage to the mitochondria as judged by their retention of glutamate dehydrogenase, and their ability to accumulate and retain Ca2+ in the absence of ruthenium red and EGTA. The data indicate that about 13% of total cell Ca2+ only may be mitochondrial in vivo.     

Developmental delays in exploration and locomotor activity in male rats exposed to low level lead

Delays in the development of exploratory and locomotor behavior in neonatal male rats (up to 21 days of age) are shown to accrue as a consequence of low level lead exposure. Cross fostering experiments indicate that these delays are primarily due to prenatal exposure. These Pb induced behavioral modifications appear to be associated with the delays in synaptogenesis and biochemical development of the cerebral cortex reported previously (4, 18). A new behavioral bioassay for detecting delays in brain development is described.     

Altered serotonin and norepinephrine metabolism in rat dorsal raphe nucleus after drug-induced hypertension

The effect of drug-induced hypertension on neurotransmitter release from dorsal raphe nucleus was studied by in vivo electrochemical electrodes in urethane anesthetized male Sprague-Dawley rats. Carbon paste electrodes were stereotaxically placed into dorsal raphe nucleus and neurotransmitter release was estimated electrochemically. Blood pressure was recorded from a femoral arterial catheter. Voltammograms taken from dorsal raphe nucleus showed two distinct peaks corresponding to norepinephrine and 5-hydroxyindole acetic acid (5-HIAA). After basal blood pressure and neurotransmitter release were monitored for 30 min, blood pressure was raised 50 mmHg by continuous intravenous infusion of L-phenylephrine hydrochloride. Drug infusion was discontinued after 50 min, but blood pressure and neurotransmitter release were measured for an additional 2 hr. Results showed that the 5-HIAA response increased immediately after the initiation of hypertension and remained elevated. By contrast, norepinephrine release initially decreased, then returned to the basal level and then rose in parallel with 5-HIAA to a level above baseline as drug-induced hypertension was discontinued. The same experimental protocol was used to study the electrochemical response to drug-induced hypotension. Blood pressure was lowered 20 mmHg by intravenous infusion of sodium nitroprusside dihydrate. During hypotension, no changes were seen in either transmitter response. However, as reflex hypertension appeared following discontinuation of the sodium nitroprusside infusion, the 5-HIAA response increased and the norepinephrine response decreased. These results show that drug-induced and reflex hypertension reduce norepinephrine release and increase serotonin turnover in dorsal raphe nucleus in anesthetized normotensive rats. These reciprocal changes appear to be a part of the neural response to hypertension.     

Regulation of endogenously catalyzed ADP-ribosylation in adipocyte plasma membranes by Ca2+ and calmodulin

The effects of Ca2+ and calmodulin on endogenously catalyzed ADP-ribosylation were investigated in adipocyte plasma membranes. Four specific proteins of 70, 65, 61 and 52 kDa were labeled with [32P]ADP-ribose and ADP-ribosylation of the proteins was highly dependent upon the conditions employed. ADP-ribosylation of the 70 kDa protein was observed only in membranes supplemented with Ca2+. Maximal incorporation of [32P] into the protein was achieved with free Ca2+ concentrations of 90 microM. Calcium-stimulated ADP-ribosylation of the 70 kDa protein was inhibited by calmodulin. Half-maximal inhibition was observed in membranes incubated with 1.2 microM calmodulin. The effect of calmodulin was characterized by an inhibition of the incorporation of [32P]ADP-ribose as opposed to a stimulation of its removal. ADP-ribosylation of the 61 kDa protein was not altered by added Ca2+ and/or calmodulin whereas ADP-ribosylation of the 65 kDa protein was partially (50%) inhibited by free Ca2+ concentrations between 10(-6) - 10(-5) M. These results provide evidence that the adipocyte plasma membrane contains ADP-ribosyltransferase activities and demonstrate that ADP-ribosylation of a 70 kDa protein is regulated by Ca2+ and calmodulin.     

Characterization of a (Ca2+ + Mg2+)-ATPase activator bound to human erythrocyte membranes

Incubation of human erythrocyte ghosts with an equal volume of 0.2 mM EDTA in isotonic KCl decreased both the activity and Ca2+ sensitivity of the (Ca2+ + Mg2+)-ATPase remaining associated with the membrane. Readdition of the EDTA-extract activated the (Ca2+ + Mg2+)-ATPase activity. The activator activity was trypsin sensitive, heat stable and retained by a phenothiazine affinity column, consistent with properties expected of calmodulin. However, unlike calmodulin, the activity was not retained by DEAE Sephadex A-50 and it eluted from Sephacryl S-200 as heterogeneous peaks of activator activity of apparent molecular weight between 107,000 and 178,000. Nevertheless, the activator in the EDTA extract both before and after gel filtration contained calmodulin, as determined by radioimmunoassay and by its activation of calmodulin - deficient phosphodiesterase. SDS-gel electrophoresis of the activator isolated by gel filtration showed a protein of Mr 56,000 in addition to a low molecular weight protein corresponding to calmodulin. It is suggested that the red cell membrane contains a calmodulin binding protein which tightly binds calmodulin as a polymeric complex in a Ca2+-independent manner.     

Wound healing in the cornea of the chick embryo: III. The influence of pore size of millipore filters on the migration of isolated epithelial sheets in culture

The migratory activity of epithelia isolated from the cornea and the dorsal skin of chick embryos of different ages was examined in vitro. Five types of Millipore filters differing in pore size served as models to represent degrees of unevenness of the substrate instead of the natural wound beds of the corneal stroma and the dorsal dermis. Migration of the epithelium was rapid and extensive when the pore size was below 0.8 μm, but was inhibited or stopped when the pore size reached or exceeded 0.8 μm. The effect of surface properties of the substratum on the motility of the cell membrane and thus on the movement of the cells is discussed.     

Reversal of amphetamine-induced circling preference in trained circling rats

Others have shown that amphetamine given to normal rats causes turning in a particular, preferred direction in most animals. We have studied the effect of training on amphetamine-induced behavioral and biochemical asymmetries in male Sprague-Dawley rats. Water deprived animals were trained to circle either in the same or opposite direction to their intrinsic bias using a sucrose water reward. Acquisition of the learned circling behavior was independent of turning preference and all animals were able to make the operant association. After training, animals given amphetamine turned in the trained direction regardless of their previous circling preference. Amphetamine-induced circling also led to increased dopamine concentrations in caudate contralateral to the trained circling direction. Therefore, intrinsic striatal is not resistant to behavioral modification and both the behavioral and biochemical asymmetries can be resersed by circling training.     

An observational study of scent-marking in coyotes, Canis latrans

Urination and defaecation patterns of free-ranging coyotes (Canis latrans) were studied in the Grand Teton National Park, Jackson, Wyoming, for two years. The vast majority of urinations by adult males and females were involved in ‘marking’, and differentiating between ‘marking’ and ‘elimination’ may not be necessary. Our results may be summarized as follows: (1) raised-leg urinations (RLU) performed by males were most frequently used in marking. (2) Females marked throughout the year using the squat (SQU) posture. (3) Snow tracking and reading snow sign resulted in a gross underestimate of the relative frequency of SQU's and a large overestimate in the relative frequency of defaecations (DEF) when compared to results obtained by direct observation. (4) There was sexual dimorphism for the contexts in which marking occurred. Overall, marking by males was associated with courtship and mating, with travelling, and with aggression. Marking by females was associated with the acquisition and possession of food and with the denning season. (5) Marking rates per coyote increased in groups larger than two animals. (6) RLU marking rates were greatest in areas of high intrusion when compared to denning areas and areas in which non-group members infrequently tresscent odours are important in orienting individuals in space but do not represent in and of themselves barriers to movement.     

Characteristics of Ca2+ uptake in mitochondria of brown adipose tissue

The rate of calcium uptake in brown adipose tissue mitochondria is here shown to be a sensitive parameter of energisation in this tissue, as demonstrated by high susceptibility to purine nucleotides and albumin. Complete uptake of low amounts of calcium generally requires added phosphate. Bicarbonate can at least partially substitute for phosphate, whereas acetate cannot. Calcium transport in brown fat mitochondria is of interest due to recent indications of an important role of this organelle in regulation of cytosolic calcium levels.     

Myocardial function during hypoxia: Effects of dimethyl sulfoxide (DMSO) and different buffers

Stimulated rabbit left atria in various buffer solutions [bicarbonate, Tris (hydroxymethyl) aminomethane (Tris), or both] in the presence or absence of 0.84 (6%) dimethyl sulfoxide (DMSO) were subjected to mild or severe hypoxia. Contractile strength and baseline tone changes were measured and analyzed. Oxygen consumption of right and left atria was measured before and after hypoxia in the above mentioned solutions. Results indicate (1) that DMSO allows cardiac muscle to maintain contractility during hypoxia, (2) that the absence of bicarbonate during hypoxia compromises tissue function, and (3) that Tris can exhibit toxic effects which are increased in the presence of DMSO.     

Ionomycin-mediated calcium transport in rigid and fluid liposomes

The antibiotic ionophore ionomycin translocates Ca from an aqueous medium into or across an organic immiscible phase. At pH 8.0, ionomycin translocates less Ca than A23187, the effects of these ionophores being additive to one another. The capacity of ionomycin to translocate Ca across the organic phase is dramatically decreased when the pH of the aqueous media is reduced from 8.0 to 7.5 or lower values. Ionomycin also mediates Ca exchange-diffusion in liposomes, the magnitude of such a process being greater in fluid than in rigid liposomes. At a physiological pH (7.4), ionomycin is unexpectedly as potent as A23187 in mediating Ca transport in fluid liposomes. These findings suggest that the capacity of ionophores to translocate Ca across model membranes depends on both the transverse and lateral mobility of the ionophoretic molecules. The relative importance of the latter phenomenon itself largely depends on the stoichiometry of the Ca-ionophore complex.     

Transfer of chromosomal material. Association of rescuable sarcoma virus genome with chromosomal fraction

An attempt was made to transfer the murine sarcoma virus genome from cryptically transformed HT-1 cells to hamster embryo cells via isolated chromosomes (chromosome immigration). Chromosome immigration did not result in any transformation of recipient embryo cells. However, there was transfer of a rescuable sarcoma virus genome. Evidence indicates that the transfer requires the intact chromosome structure. It was not possible to identify one or any chromosome associated with the rescuable sarcoma genome.     

Two-act transitions,partitioned contingency tables,and the ‘significant cells’ problem

When contingency tables of data on sequences, social relationships, feeding, habitat use, or other behaviour exhibit significant associations between variables, ethologists may analyse the residuals in the table in order to test more precise hypotheses about the associations found. This paper critically evaluates currently used and potentially available statistical methods for performing such tests. Specific examples of use are given and recommendations made.     

LH response of seasonally anovular Corriedale ewes acutely exposed to rams and estrous ewes

Serial blood sampling before and after exposing four anovular Corriedale ewes to a group of rams and estrous ewes during the non-breeding season revealed a pattern of LH secretion similar to that previously observed in Merinos. Mean LH values doubled (P<0.001) from 0.24+/-0.06 microgL(-1) (mean+/-s.e.m.) before to 0.55+/-0.05 microgL(-1) after 2h of visual, auditory, and odor exposure to rams and estrous ewes in an indoor facility. A non-significant (P<0.17) increase of LH pulses per hour was also observed (0.7+/-0.3 pulses per hour before compared with 1.3+/-0.3 during stimulation). All four ewes had recently formed corpora lutea by five days after stimulation. Results are consistent with the pattern of sudden increase and sustained release of LH observed in other sheep breeds, particularly the Merino.     

Evidence for two classes of rat plasma fibrinogen γ chains differing by their COOH-terminal amino acid sequences

Human fibrinogen molecules contain two classes of functionally equivalent γ chains (termed γ and γ′) differing by their COOH-terminal amino acid sequences. We investigated rat plasma fibrinogen for the presence of this heterogeneity using DEAE-cellulose chromatography to separate reduced S-carboxymethylated chains. Like human γ′ chains, rat γ′ chains were more negatively charged, somewhat larger (～1000 daltons), had a different COOH-terminal acid than γ chains, and were functionally equivalent to other γ chains. The γ′ chain population from normal and turpentine-stimulated animals amounted to 28 and 30% of all γ chains, respectively, suggesting that regulation of their production is not sensitive to stimulation of fibrinogen synthesis.     

Aggressive behaviour of female prairie deer mice in laboratory populations

Prairie deer mice (Peromyscus maniculatus bairdii), living in asymptotic laboratory populations established two years earlier, were observed for agonistic responses to conspecific intruders. In the first experiment, intruders of six age-sex classes were placed into 10 of the populations for 10 min. The sex of the intruder did not influence the behaviour of the residents, but juveniles elicited more aggression than did adults. A second experiment revealed that female residents were responsible for almost all of the attacks upon juveniles. Experiment 3, in which the responses of pairs of deer mice to juvenile intruders were recorded, demonstrated that the aggressiveness of a female was enhanced by the presence of a male. In the final experiment, females were observed to be highly aggressive during the first few days after giving birth. The aggressive behaviour of the female deer mouse may have greater significance for population dynamics than that of the male.     

Demonstration of specific high affinity binding sites for [3H] imipramine in human brain

High affinity binding sites (Kd = 1.7 nM) for [³H] imipramine have been characterized in membranes prepared from human brain. The binding of [³H] imipramine was found to be saturable, reversible, and inhibited by pharmacologically active tricyclic antidepressants. Other psychoactive compounds as well as most neurotransmitter substances were ineffective in inhibiting [³H] imipramine binding at concentrations up to 10 μM. The hypothalamus was found to contain a relatively high density of these binding sites and is enriched approximately 4-fold when compared to cerebral and cerebellar cortex. A very good correlation (r = 0.97) p < 0.001 was found between the abilities of a series of clinically active tricyclic antidepressants in displacing specifically bound [³H] imipramine from human brain and platelet membranes, suggesting that the binding sites from these two tissues are very similar.     

The variability of some motor components of social play and agonistic behaviour in infant eastern coyotes, Canis latrans var

The duration and stereotypy (in terms of duration) of three actions, stand-overs (SO), generalbites (GB), And scruff-bites (SB), were measured during social play and agonistic interactions in infant eastern coyotes (Canis latrans). The rate of biting was also calculated. We found: (1) SO's and GB's lasted a significantly shorter time during play; (2) when performed during playful interactions, all three acts showed more stereotypy; (3) there was no significant difference between the rates of occurrence of biting during the two situations. A discussion of the 'exaggerated' nature of play behaviour is presented, particularly concerning the form of motor actions that are used during this activity.