Thirst: neuroendocrine regulation in mammals

Animals can sense their changing internal needs and then generate specific physiological and behavioural responses in order to restore homeostasis. Water-saline homeostasis derives from balances of water and sodium intake and output (drinking and diuresis, salt appetite and natriuresis), maintaining an appropriate composition and volume of extracellular fluid. Thirst is the sensation which drives to seek and consume water, regulated in the central nervous system by both neural and chemical signals. Water and electrolyte homeostasis depends on finely tuned physiological mechanisms, mainly susceptible to plasma Na+ concentration and osmotic pressure, but also to blood volume and arterial pressure. Increases of osmotic pressure as slight as 1-2% are enough to induce thirst ("homeostatic" or cellular), by activation of specialized osmoreceptors in the circumventricular organs, outside the blood-brain barrier. Presystemic anticipatory signals (by oropharyngeal or gastrointestinal receptors) inhibit thirst when fluids are ingested, or stimulate thirst associated with food intake. Hypovolemia, arterial hypotension, Angiotensin II stimulate thirst ("hypovolemic thirst", "extracellular dehydration"). Hypervolemia, hypertension, Atrial Natriuretic Peptide inhibit thirst. Circadian rhythms of thirst are also detectable, driven by suprachiasmatic nucleus in the hypothalamus. Such homeostasis and other fundamental physiological functions (cardiocircolatory, thermoregulation, food intake) are highly interdependent.

Interactive classroom: from motoneuron activity to skeletal muscle contraction and relaxation

Active learning and practices are strongly encouraged or made mandatory by local, national, and european organizations. Therefore, we set up an interactive practical classroom, engaging all of the attending students of the year (n = 47). Each student was assigned a physiological role (marked on a cardboard sign) in the following events: stimulation on motoneuron dendrites, sodium ions (Na⁺) influx and potassium ions (K⁺) efflux, action potentials onset and saltatory conduction along the axon, acetylcholine (Ach) neurotransmitter exocytosis following Ca⁺⁺ influx, Ach binding to postsynaptic membrane receptors, Ach-esterase action, excitatory post-synaptic potential (EPSP), release of Ca⁺⁺ from the sarcoplasmic reticulum, mechanism of muscular contraction and relaxation, rigor mortis. A sketch was drawn with colored chalks on the ground outside the room: the motoneuron with its dendrites, cell body, initial segment, myelinated axon, synaptic bouton, the postsynaptic plasma membrane of the muscle fiber and the sarcoplasmic reticulum. Students each had their own role and were asked to position themselves and move, accordingly. This resulted in a complete, dynamic and fluid representation being performed. The evaluation of the effectiveness of the students' learning was limited at this pilot stage. However, positive feedback was received in the self-evaluation reports which were written by students on the physiological meaning of their own role, as well as in the satisfaction questionnaires requested by the University. The rate of students who successfully passed the written exam and the rate of correct answers that included the specific topics addressed in this practice were reported.

Blood thyroid hormones, insulin and leptin, metabolites and enzymes in transition dairy ewes, as affected by dietary linseed and physiological stage

This study investigated the effects of dietary linseed and physiological state on blood concentrations of some metabolic hormones and indicators, in transition dairy ewes. From 21 d before lambing to 60 d post-partum, ewes were provided with one of three isoenergetic and iso‑nitrogenous pelleted concentrates, without (CTR, n = 21), or with 100 (EL-10, n = 22) or 200 g/kg (EL-20, n = 22) of extruded linseed. Animals were fed alfalfa hay ad libitum and had access to mixed pasture. Plasma thyroid hormones and insulin concentrations were not affected by diet and significantly changed by time. The last week of pregnancy T3 (2.27 ± 0.15 ng/mL) and T4 (102.63 ± 2.85 ng/mL) were lower than at 4 weeks before lambing (T3: 3.27 ± 0.27 ng/mL; T4: 125.89 ± 2.63 ng/mL). After lambing, T3 rose to be highest at 4 and 8 weeks of lactation (3.41 ± 0.22). Mean insulin peaked 2 weeks after lambing (0.31 ± 0.02 ng/mL) vs. late pregnancy (0.22 ± 0.01 ng/mL) and progressing lactation (0.18 ± 0.01 ng/mL). Plasma Leptin concentration (2.43 ± 0.03 ng/mL) was not affected by diet nor time. All the blood metabolites and enzymes investigated showed significant time x treatment interaction. Differences of several haematological parameters were found in EL vs. CTR (cholesterol, triglycerides, total protein, bilirubin, ALP, ALT), however, in most cases the values were fairly within the reference physiological ranges. Metabolic hormones are confirmed to be mainly linked to the different physiological states, energy intake and variations of energy balance, without clear effects by different sources of energy and quality of dietary lipids.

Distribution of selected trace elements in the major fractions of donkey milk

The aim of this study was to evaluate the concentrations of Zn, Cu, Mn, Se, Mo, Co, Li, B, Ti, Cr, Rb, Sr, Cd, and Pb in donkey milk and their distribution in major milk fractions (i.e., fat, casein, whey proteins, and aqueous phase). Individual milk samples were provided by 16 clinically healthy lactating donkeys. Subsequent centrifugation, ultracentrifugation, and ultrafiltration were carried out to remove fat, casein, and whey proteins to obtain skim milk, a supernatant whey fraction, and the aqueous phase of milk, respectively. Concentrations of the elements were measured in whole milk and fractions by inductively coupled plasma-mass spectrometry, and the concentrations associated with fat, casein, and whey proteins were then calculated. The effect of removal of fat, casein, and whey proteins was determined by repeated-measures ANOVA. The fat fraction of donkey milk carried a small (∼4.5% to 13.5%) but significant proportion of Mo, Co, Ti, Cr, and Sr. The casein fraction in donkey milk carried almost all milk Zn, a majority of Cu and Mn, and most of Mo, Ti, and Sr. Relevant proportions, between 20% and 36%, of Se, Co, and Cr were also associated with caseins. The majority of Se, Co, Li, B, Cr, and Rb, and relevant proportions of Mn, Mo, Ti, and Sr were found in soluble form (ultracentrifuged samples) and distributed between whey proteins and the aqueous phase of milk (ultrafiltered samples). Whey proteins in donkey milk carried the majority of milk Se and Co. All Li and B was present in the aqueous phase of milk, which also contained most Rb and Cr, and 17% to 42% of Mn, Se, Mo, Co, Ti, and Sr.

A leptin sandwich ELISA kit unusable for domestic animals

An instance of hormone assay method flaw is reported. In this journal Chronobiology International, two papers appeared in which an ELISA method for human serum or plasma was utilized for blood serum of horse and sheep, respectively. From our testing, it is resulted that such method does not work at all for equine, sheep and other animal species. The use of commercial hormone assay kits for heterologous species always needs a careful validation procedure. First, the same hormone molecule by different species could not share enough homology to be regognized by and react with antibodies utilized in the method. Furthermore, even with a full overlap of the molecules, possible interferences by other components of the sample (matrix effect) have to be considered.

Distribution of calcium, phosphorus, sulfur, magnesium, potassium, and sodium in major fractions of donkey milk

The aim of this study was to evaluate the concentrations of Ca, P, S, Mg, K, and Na, and their distribution in major fractions of donkey milk (i.e., fat, casein, whey proteins, and aqueous phase). Individual milk samples were collected by mechanical milking from 16 clinically healthy lactating donkeys. Milk yield per milking was recorded and milk gross composition, casein content, and pH were determined. Whole milk samples were centrifuged to separate fat and to obtain skim milk. Skim milk samples were ultracentrifuged to separate a sedimentable casein pellet and to obtain a supernatant whey (soluble) fraction, which was then ultrafiltered to obtain the aqueous phase of donkey milk. Whole milk and the processed samples were analyzed for the aforementioned elements by inductively coupled plasma-mass spectrometry. The concentration of elements associated with fat, casein, and whey proteins was then calculated. All the Na was present in the aqueous phase. The fat fraction in donkey milk carried very little or none of the investigated elements. The majority of Ca (62.9%) and P (53.1%) was associated with casein, and the rest of these elements was mostly present in the aqueous phase. The majority of Mg was present in the aqueous phase, but a relevant part (32.6%) was associated with the casein fraction. No K was associated with casein. On a molar basis, the ratio of colloidal Ca and P to casein (mmol/g of casein) was more than double the values reported in literature for cow milk. The correlation coefficient was negative between milk pH and P in the ultracentrifuged (r = -0.81) and ultrafiltered (aqueous) fraction (r = -0.66). Milk pH correlated positively with colloidal Ca (r = 0.59) and with the ratio of colloidal Ca to casein (mmol/g of casein; r = 0.68). Colloidal Ca and P were positively correlated (r = 0.64). These data suggest that the high ratio of colloidal Ca and P to donkey casein micelles is due to a larger amount of colloidal calcium phosphate bound to casein micelles compared with literature data on cow milk. The percentage of elements associated with whey proteins was less than 5% for Ca, P, and K, but Mg reached approximately 9% of total Mg. The majority of S (63.6%) was associated with whey proteins, and only one-fourth of this element was associated with casein, indicating a higher content of sulfur-containing amino acids in donkey whey proteins than in casein.

Dietary integration with oregano (Origanum vulgare L.) essential oil improves growth rate and oxidative status in outdoor-reared, but not indoor-reared, pigs

The effects of a diet supplemented with oregano essential oil on performance, oxidative status, pork quality traits and sensorial properties were evaluated. In two studies, 72 pigs in indoor or outdoor conditions were assigned to either a control diet or an identical diet supplemented with 0.2% oregano essential oil. Pigs reared outdoor showed lower live weight, average daily gain and average gain:feed ratio compared to indoor pigs. The oregano supplementation improved the growth performance of the outdoor- but not the indoor-reared animals. The serum oxidative status was influenced by the diet. A higher oxidative stability was observed in the oregano-supplemented groups. As for the rearing conditions, the data suggest that after an initial adapting period, the free-range farming systems could be better tolerated by pigs. Meat derived from pigs reared outdoor showed higher pH and a* values. Lightness was influenced by both the diet and the rearing conditions. The control group reared indoor showed shear force values higher than both supplemented groups, while no differences were detected with the control group reared outdoor. In the consumer test performed under blind conditions, the oregano groups achieved higher consistency scores compared with the control. Under informed conditions, the meat derived from the oregano-supplemented pigs reared outdoor received the highest scores for consistency and overall liking regardless of the rearing system. The same result for the overall liking score was obtained in the expectation test. The data obtained showed that dietary oregano essential oil can be effective in reducing performance losses due to the outdoor-rearing system, increasing the oxidative status of the animal and oxidative stability of the meat, without modifying the meat quality traits and improving consumer perceptions of the meat quality.

On the role of noradrenergic system in PTSD and related sleep disturbances. The use of terazosin in PTSD related nightmares: a case report

In PTSD, sleep disorders represent an important symptoms dimension which is associated with more severe PTSD and increased risk of relapse. The basic treatment for PTSD is not always associated to an improvement of sleep disturbances and nightmares. Alpha-blockers, and more specifically Prazosin, have shown a specific action on sleep disorders in PTSD. We report the clinical case of a young women with PTSD, who was suffering from severe sleep disorder and distressing nightmare. The patient was treated with Terazosin, a conger of Prazosin, and has shown symptom remission. Further studies on the use of alpha-blokers might reveal new therapeutic options in PTSD.

[Drug abuse and adolescence: neurobiology and psychiatric implications]

Drug abuse in adolescence is a main public health concern. About 60% of people who abuse substances is younger than 18 years old. Early addiction increases other drug abuse and it is associated to greater risk in the development of Substance Use Disorders and psychiatric disorders. In the management of adolescent addiction, the awareness of recent researches on alcohol, cannabis, cocaine and methamphetamine abuse, can represent a fundamental tool in terms of prevention, early detection and treatment for clinicians, researches and parents.

[Psychiatric emergencies: guidelines for the treatment of agitation]

Psychomotor agitation represents a common phenomenon in emergency psychiatry settings. The awareness of its clinical manifestations and the early management can permit the control over a potentially dangerous behavior that could otherwise convert itself into a violent one. Health professionals should be able to adopt de-escalation strategies, structured to achieve the stabilization of patients' aggressiveness and motor agitation. When abnormal behaviors persist clinicians should be competent in the adoption of the most adequate psychopharmacological treatment for patient de-escalation. In this work we analyze psychomotor agitation treatment guide-lines.

[Depression and cardiovascular risk. Relationship, pathogenetic mechanisms, treatment and patient management. A review of the literature]

Depression is more frequent and also associated with a worse prognosis, in patient suffering from coronary artery disease. Although growing researches have been performed in the last year, confirming the importance of this association, the causal mechanisms still remains not fully understood. The treatment and patient management represents another not clarified issue. In this review of the literature we analyze the connections between depression and cardiovascular disease in terms of possible pathophysiological mechanism, cardiovascular prognosis, treatment and patient management.

Effects of field bean (Vicia faba L. var. minor) dietary supplementation on plasma thyroid hormones, insulin, insulin-like growth factor-1 concentrations and mohair characteristics in growing Angora goat kids

Twenty-two Angora kids were used to study the effect of a dietary supplementation with field bean (Vicia faba L. var. minor) on hair follicle activity, mohair characteristics and plasma total thyroxine (T4), triiodothyronine (T3), insulin (INS) and insulin-like growth factor-1 (IGF-1) concentrations. At birth, their mothers were divided in two groups (S: supplemented, C: control), the S group being supplemented with 300 g/head/day of whole field bean. At weaning, diet of kids from S group was supplemented with 80 g/head/day of whole field bean. At weaning, secondary hair follicle activity (S: 0.91 ± 0.01, C: 0.84 ± 0.02, p < 0.01) and staple length (S: 5.82 ± 0.13 cm, C: 5.16 ± 0.14 cm, p < 0.001) were greater in the S group. At 155 days of age, secondary fibre diameter (S: 16.54 ± 0.35 μm, C: 18.09 ± 0.31 μm, p < 0.01) was higher in the C kids. Concentrations of total plasma T4 and T3 were higher (p < 0.001) in S (120 ± 12 and 4.87 ± 0.92 ng/ml respectively) than in C kids (92 ± 8 and 2.97 ± 0.77 ng/ml respectively). At weaning, T4 values were negatively correlated (p < 0.05) with the secondary fibre diameter and the T3/T4 ratio was positively correlated (p < 0.05) with the secondary to primary hair follicle ratio. At 155 days of age, both T3 and T3/T4 values were positively correlated (p < 0.01) with staple length. Plasma INS (0.11 ± 0.03 ng/ml) and total IGF-1 concentrations (232 ± 13 ng/ml) were not affected by diet. Improvements of diet quality in kids positively affected fibre diameter and length and follicle activity rate. We suggest that increased circulating thyroid hormones concentrations, but not those of INS and IGF-1, may contribute to the beneficial actions of nutritional supplementation on anatomical growth and mohair production of kids.

Validation of a new pregnancy-associated glycoprotein radioimmunoassay method for the detection of early pregnancy in ewes

The aim of the current study was to describe the use of a pool of different antisera raised against pregnancy-associated glycoproteins (PAGs; purified from both ovine and caprine placentas) for early pregnancy diagnosis in ovine species. Sixty-three pluriparous Sarda ewes (Ovis aries) were synchronized. Blood samples were withdrawn on Days 18, 24, 26, 28, 30, and 50 after mating. These samples were assayed for progesterone (radioimmunoassay [RIA] including an extraction step) and for pregnancy-associated glycoproteins (RIA-706 and RIA-srPool). Progesterone concentrations were under 1.0 ng/mL in all nonpregnant Sarda ewes. In pregnant ewes, mean progesterone concentrations ranged from 2.4 ng/mL (Day 24, single pregnancies) to 4.4 ng/mL (Day 28, multiple pregnancies). During all periods of examination, PAGs remained lower than 0.8 ng/mL in nonpregnant ewes. On Day 18 of pregnancy, PAG concentrations could be detected in 26 of 43 (60.5%) and in 41 of 43 (95.3%) pregnant ewes using the RIA-706 and RIA-srPool methods, respectively. From Day 24 to Day 50, using both RIA methods, PAGs could be detected in all pregnant ewes. On Day 24, the best threshold for pregnancy diagnosis was obtained by use of RIA-srPool, maximal concentration in nonpregnant ewes being 0.3 ng/mL and minimal concentration in pregnant ewes being 4.8 ng/mL. In general, progesterone and PAG concentrations were higher in multiple pregnancies than in single pregnancies. However, because of large individual variations, single pregnancies could not be differentiated from multiple pregnancies.

Seasonality of plasma testosterone in males of four Mediterranean goat breeds and in three different climatic conditions

The aims of the present work were to evaluate if a seasonality of plasma testosterone concentrations exists in Mediterranean male goats and it may be affected by climatic conditions. Testosterone concentrations were determined throughout 1 year in blood samples collected weekly from 24 males of 4 Mediterranean goat breeds (Ionica, Garganica, Maltese and Red Syrian), fed a constant diet, maintained without interactions with does and reared in 3 farms with different climates, in Italy. Plasma testosterone concentrations were affected by season (P<0.0001), being higher during summer (8.33+/-0.35 ng/mL) than during autumn (6.81+/-0.26 ng/mL), which were in turn higher than in winter (1.55+/-0.08 ng/mL) and spring (2.04+/-0.15 ng/mL). An effect of breed was recorded (P<0.001), Ionica bucks having the highest plasma testosterone means, Red Syrian and Maltese the lowest. The onset of the reproductive season was similar among the breeds. Ionica bucks had a later offset than Red Syrian and Maltese and a longer reproductive season than Maltese bucks (P<0.05). No effect of farm nor interaction breed x farm was recorded. Single sporadic peaks of plasma testosterone were recorded in many bucks, outside the main reproductive season, especially during spring. In conclusion the bucks of all the four breeds displayed a clear seasonality of plasma testosterone, with very low levels from January to May and high levels from July to November; hormone levels and pattern of seasonality were affected by breed and not by climate.

Progesterone plus PMSG Priming in seasonally anovulatory lactating Sarda ewes exposed to the ram effect

The aim of this trial was to evaluate the effectiveness (fertility and lambing) of priming with a single injection of progesterone plus PMSG in anovulatory lactating Sarda ewes subjected to the ram effect (RE) in spring. Thirty ewes (P4 group) were i.m. injected with 30 mg progesterone and 500 IU PMSG 36 h before ram introduction (d 0). This treatment was compared to a 12-day treatment with fluorogestone acetate intravaginal sponges that was followed by injections of 350 IU PMSG upon sponge withdrawal (FGA group, n=30). All ewes responded to RE, showing plasma progestrone concentrations >1 ng/mL between d 6 and 12 (FGA) or 6 and 9 (P4). Eighty-nine percent of the P4 ewes conceived at first ovulation, and 11% conceived following a short estrus cycle. Lambings occurred on d 150.4 +/- 3.9, and the lambing rate was 100%. The fertility of the FGA ewes was 83% for the induced ovulation and was 7% for the second ovulation after a normal cycle. The FGA ewes lambed on d 149.8 +/- 4.4, and the lambing rate was 83%. Two abortions were recorded for the FGA ewes, which had higher prolificacy than the P4 group (2.2 +/- 0.8 vs. 1.8 +/- 0.4, respectively; P<0.05). Both fertility and the lambing rate were high in both groups, with a high degree of estrus synchronization, and there were no significant differences between the groups. We concluded that priming of lactating Sarda ewes in spring with P4+PMSG before RE is an effective and competitive method (cheaper and more practical than FGA+PMSG) of inducing fertile ovulations in these ewes.

Blood testosterone levels in Italian Mediterranean buffalo bulls managed in two different breeding conditions

In Italian buffalo cows the spontaneous cyclic ovarian activity is mainly high in autumn, while during spring and early summer it is very low. However many farmers separate males from females in the October-February period to obtain births in winter-spring. In order to verify if blood testosterone concentration in adult buffalo bulls is affected by season and by different management of the contact with females, 20 adult buffalo males, bred in central Italy were submitted to monthly blood sampling for 1 year, from September to August. The bulls were kept together with females all the time (group A; n=9) or were held separated from cows from October to February (group B; n=11). The mean (+/-S.E.M.) serum testosterone concentrations were higher in spring and summer than in autumn and winter in group B (2.07+/-0.1 ng/mL versus 0.99+/-0.08 ng/mL, P<0.01) but in group A the seasonal difference was not significant (2.09+/-0.13 versus 1.48+/-0.28). The management of the contact with females affected testosterone values (P<0.01): in the separation period (October-February) the mean serum concentration in group B was lower than in March-September, when the cows were together with the bulls (0.94+/-0.09 ng/mL versus 1.95+/-0.1 ng/mL, P<0.05). This is not true for group A (1.49+/-0.20 ng/mL versus 2.00+/-0.13 ng/mL, NS). It is concluded that contact with females exerted a major stimulus for the testicular androgen secretion in buffalo bulls, even if other seasonal factors (climate, food intake) may affect control of gonadal activity.

Histochemical detection of the lectin-binding carbohydrates in the zona pellucida during oocyte growth in the wild boar (Sus scrofa scrofa)

The changes that occur in the carbohydrate composition of zona pellucida glycoproteins during oocyte maturation in the wild-boar were studied using periodic-acid Schiff (PAS), High Iron Diamine (HID) and Low Iron Diamine (LID). Lectin staining was performed with a panel of 11 HRP-lectin conjugates combined with neuraminidase digestion and chemical treatments. There were few internal glucidic residues, such as N-acetylglucosamine, in the wild boar zona pellucida but there were many subterminal beta-N-acetylgalactosamine, alpha- and beta-galactose determinants masked by sialic acid. In addition, beta-N-acetylgalactosamine, beta-galactose-(1-3)-N-acetylgalactosamine and beta-galactose-(1-4)-N-acetylglucosamine were detected in the sulphated form in the terminal and/or subterminal position. Some differences in the lectin reactive sites occurred in the zona pellucida, depending on the stage of oocyte maturation.