Phosphorus balance and fecal losses in growing Standardbred horses in training fed forage-only diets.

This study examined the P balance and fecal P losses in growing Standardbred horses in training fed a forage-only diet with or without P supplementation and assessed the magnitude and proportion of the soluble, inorganic P (Pi) fraction in feces. Fourteen Standardbred horses (aged 20.0 ± 0.3 mo) adapted to ad libitum intake of grass forage containing 0.25% P were used in a crossover experiment investigating 2 dietary treatments with (high-P) and without (low-P) mineral supplementation for 6 d. Daily feed intake and refusals were weighed. Spot samples of feces were collected twice daily on d 4 to 6 and analyzed for total P and Pi. Acid-insoluble ash was used as a marker for total fecal output. Spot samples of urine were collected once on d 4 to 6 and analyzed for P and creatinine. Daily P intake was greater (P < 0.001) for the high-P diet (32.0 ± 0.6 g) than the low-P diet (17.5 ± 0.6 g), and the individual intake ranged from 13.3 to 38.4 g/d. Total fecal excretion of P was also greater (P < 0.001) for the high-P diet (30.3 ± 0.8 g/d) than the low-P diet (17.0 ± 0.8 g/d) whereas excretion in urine was less than 0.2 g/d on both diets. Using simple regression analysis, fecal endogenous P losses were estimated to be less than 10 mg/kg BW. Phosphorus retention was 1.6 ± 0.6 and 0.3 ± 0.6 g/d on the high- and low-P diets, respectively, but only that for the high-P diet was greater (P < 0.05) than 0 g/d. The proportion of Pi of total fecal P excretion was 100 ± 3% for the high-P diet and 87 ± 3% for the low-P diet (P = 0.005) and Pi increased linearly with P intake (y = 1.10x - 4.44; r(2) = 0.91; CV = 9.9%; P < 0.001). In conclusion, on this forage-only diet significant retention of P occurred at a daily P intake of 7.1 g/100 kg BW. Phosphorus was mainly excreted in feces and both total fecal P and Pi excretion had a strong relationship to P intake. More than 80% of total P appeared to be soluble. Fecal endogenous P losses were similar to those described previously in growing horses.

Growth, training response and health in Standardbred yearlings fed a forage-only diet.

The aim of this study was to, from a holistic perspective, describe the effects of a forage-only feeding system and a conventional training program on young Standardbred horses and compare data with similar observations from the literature. Sixteen Standardbred colts fed a forage-only diet for 4 months from breaking (August to December) and with the goal to vigorously trot 5 to 7 km at a speed of 5.6 m/s (3 min/km) were studied. The horses were fed grass haylage (56 to 61% dry matter (DM), 2.80 to 3.02 Mcal DE/kg DM and 130 to 152 g CP/kg DM) ad libitum, 1 kg of a lucerne product and minerals. The amount of training and number of training sessions were documented daily, and feed intake and body development were measured once every month. Heart rate (HR) was measured during and after a standardized exercise test in October and December. In December, a postexercise venous blood sample was collected and analyzed for plasma lactate concentration. Muscle biopsies (m. gluteus medius) were taken and analyzed for glycogen and fiber composition. Health was assessed in October and November by an independent veterinarian using a standardized health scoring protocol. BW and height at withers increased from 402 to 453 kg (root mean square error (RMSE) 6) and from 148.7 to 154.1 cm (RMSE 0.7), respectively, and the body condition score was 4.9 (RMSE 0.2) at the end of the study. Muscle glycogen content was 532 mmol/kg dry weight (s.d. 56). There was a significant decrease in postexercise HR (81 v. 73 bpm, RMSE 8), and the individual amount of training was negatively correlated with HR during and after exercise. Health scores were high and similar at both assessments (8.4 and 8.4 (RMSE 1.0) out of 10; P > 0.05), and the number of lost training days per month due to health problems was <0.9, with the exception of November (5.3 days). It is concluded that yearlings in training fed high-energy forage ad libitum can reach a conventional training goal and grow at least as well as earlier observations on yearlings of other light breeds.

A forage-only diet alters the metabolic response of horses in training.

Most athletic horses are fed a high-starch diet despite the risk of health problems. Replacing starch concentrate with high-energy forage would alleviate these health problems, but could result in a shift in major substrates for muscle energy supply from glucose to short-chain fatty acids (SCFA) due to more hindgut fermentation of fibre. Dietary fat inclusion has previously been shown to promote aerobic energy supply during exercise, but the contribution of SCFA to exercise metabolism has received little attention. This study compared metabolic response with exercise and lactate threshold (VLa4) in horses fed a forage-only diet (F) and a more traditional high-starch, low-energy forage diet (forage-concentrate diet - FC). The hypothesis was that diet F would increase plasma acetate concentration and increase VLa4 compared with diet FC. Six Standardbred geldings in race training were used in a 29-day change-over experiment. Plasma acetate, non-esterified fatty acids (NEFA), lactate, glucose and insulin concentrations and venous pH were measured in samples collected before, during and after a treadmill exercise test (ET, day 25) and muscle glycogen concentrations before and after ET. Plasma acetate concentration was higher before and after exercise in horses on diet F compared with diet FC, and there was a tendency (P = 0.09) for increased VLa4 on diet F. Venous pH and plasma glucose concentrations during exercise were higher in horses on diet F than diet FC, as was plasma NEFA on the day after ET. Plasma insulin and muscle glycogen concentrations were lower for diet F, but glycogen utilisation was similar for the two diets. The results show that a high-energy, forage-only diet alters the metabolic response to exercise and, with the exception of lowered glycogen stores, appears to have positive rather than negative effects on performance traits.

Plasma aldosterone concentration and cardiovascular response to low sodium intake in horses in training.

REASON FOR PERFORMING THE STUDY: Horses in training lose large amounts of sodium but little is known about the cardiovascular response to low sodium intake. OBJECTIVES: To investigate the effect of low sodium intake on plasma aldosterone (pAldo) concentrations and the cardiovascular system of athletic horses, and to identify markers of low sodium intake. METHODS: Seven Standardbred geldings in training (trained twice a week) were randomly offered a standardised diet supplemented (NaS, 58 mg Na/kg bwt) and not supplemented (NaN, 3 mg Na/kg bwt) with NaCl for 5 weeks in a changeover design. Blood samples were taken once a week and in Week 5, before and following an exercise test until 22.30 h and analysed for blood sodium (bNa), total plasma protein (TPP), pAldo, troponin I and packed cell volume (PCV). Blood pressure (BP) was measured and pulse wave recorded at rest with high definition oscillometric-technique (HDO). ECG and echocardiography were recorded. Water intake was measured before and on the day of exercise and voluntary saline intake was measured for 2 days after each period. Faecal samples were taken weekly and analysed for sodium and potassium content. RESULTS: The pAldo and the PCV was higher in NaN compared to NaS. There were no differences between diets in BP, ECG, plasma troponin I and echocardiogram but HDO pulse amplitude tended to be smaller on diet NaN. Water intake was lower on diet NaN and saline intake higher. The response to exercise in bNa, pAldo, PCV and TPP was different on the 2 diets. Faecal potassium/sodium ratio was higher on NaN than on NaS. CONCLUSION: This study shows that 5 weeks of low sodium intake increased plasma aldosterone concentration and PCV but no alterations in heart function was observed. Faecal potassium/sodium ratio could be used to assess sodium status in horses.

Effects on the equine colon ecosystem of grass silage and haylage diets after an abrupt change from hay.

The objective of this study was to investigate the effect of an abrupt change from grass hay (81% DM) to grass silage (36% DM) or grass haylage (55% DM), fed at similar DM intakes, and to compare the effects of silage and haylage on the composition and activities of the colon microflora. The forages were from the same swath harvested on the same day. Four adult colon-fistulated geldings were randomly assigned to diets in a crossover design. The study started with a preperiod when all 4 horses received the hay diet, followed by an abrupt feed change to the haylage diet for 2 horses and the silage diet for 2 horses. All 4 horses then had a new second preperiod of hay, followed by an abrupt feed change to the opposite haylage and silage diet. The periods were 21 d long, and the forage-only diets were supplemented with minerals and salt. The abrupt feed changes were made at 0800 h. Colon samples were taken before the abrupt feed change, 4 and 28 h after the feed change, and 8, 15, and 21 d after the feed change, all at 1200 h. Colon bacterial counts, VFA, pH, and DM concentrations were unchanged throughout the first 28 h after the abrupt feed change from hay to haylage and silage. Also, fecal pH and DM concentrations were unchanged during the first 28 h. During the weekly observations, colon lactobacilli counts increased (P = 0.023) in horses receiving the silage diet and were greater than on the haylage diet at 21 d. Streptococci counts decreased (P = 0.046) in horses receiving the haylage diet and were less than on the silage diet at 15 and 21 d. Total VFA concentrations and colon and fecal pH did not differ between diets and were unchanged throughout the weekly observations. The DM concentration of colon digesta and feces decreased (P = 0.030 and 0.049, respectively) on both diets during the weekly observations. The results suggest that in horses fed at the maintenance level of energy intake, an abrupt feed change from grass hay to grass silage or grass haylage from the same crop does not induce any major alterations in the colon ecosystem during the first 28 h. During the subsequent 3-wk period, colon and fecal DM decreased and there were alterations in the lactobacilli and streptococci bacterial counts. The changes in lactobacilli and streptococci counts need further investigation.

Effects of isoflurane on prefrontal acetylcholine release and hypothalamic Fos response in young adult and aged rats.

This experiment investigated the influence of age on prefrontal acetylcholine (ACh) release and Fos response in the hypothalamic paraventricular nucleus and the nucleus tractus solitarius (NTS) of rats following isoflurane anesthesia. It is known that isoflurane decreases acetylcholine release in most brain regions. In the present study, we found that the level of prefrontal acetylcholine was significantly lower in 28-month-old rats (14% of baseline) than in 3-month-old rats (38% of baseline) during 2 h of isoflurane anesthesia (P < 0.05). The old rat group showed significantly greater Fos induction in the paraventricular nucleus compared to the young adult rat group (P < 0.05), indicating that the old rats were subjected to stress. No difference in Fos response was noted in the nucleus tractus solitarius. The old rats displayed a significant increase in feeding behavior during the 3-h recovery period (P < 0.05), but there was no difference in overall acetylcholine levels. Taken together, these findings suggest that isoflurane anesthesia influences old rats more profoundly than young adult rats with regard to reductions in acetylcholine release and stress responses. This may have implications for understanding the development of postoperative delirium in aged patients.

Effect of molassed sugar beet pulp on nutrient utilisation and metabolic parameters during exercise.

The aim of this study was to investigate the effect of partly replacing oats with molassed sugar beet pulp in a traditional hay/oat diet on nutrient utilisation and metabolic parameters in exercising horses. In a change-over experiment, 4 Standardbred geldings were fed a hay and oat-based diet (Oat diet) and a hay and oat-based diet where oats was partially replaced with molassed sugar beet pulp (MSBP diet). Each experimental period was 21 days during which total collection of faeces and urine was made and an exercise test (ET) performed. The crude fat digestibility was lower on the MSBP diet (P<0.05), while there were no differences in digestibility of other nutrients and energy and in the urinary excretion of nitrogen and energy. At rest plasma insulin were lower (P<0.05) 60 and 90 min postprandially on the MSBP diet, while no differences were found in plasma glucose and insulin between the diets during the ET. The peak plasma and muscle lactate values were lower (P<0.05) on the MSBP diet and the content of muscle glycogen was higher (P<0.05) after the ET on the MSBP diet. In conclusion, the metabolic response differed between diets giving a lower lactate response and a higher glycogen content in muscle after exercise on the MSBP diet. This suggests that the dietary carbohydrate composition may influence the rate of glycogenolysis with lactate production and support the hypothesis that MSBP can replace oats in a hay based diet without impairing nutrient utilisation and metabolic response in exercising horses.

N,N'-diacetyl-L-cystine (DiNAC), the disulphide dimer of N-acetylcysteine, inhibits atherosclerosis in WHHL rabbits: evidence for immunomodulatory agents as a new approach to prevent atherosclerosis.

Oxidation of lipoprotein-derived lipids is generally accepted to be important in atherogenesis, and lipophilic antioxidants have been suggested as potential antiatherosclerotic agents. The antiatherogenic effects observed by certain antioxidants, especially probucol, in different animal models support this suggestion. There are however also cases where other lipophilic antioxidants have not been able to support this hypothesis. This has raised the question whether the effects of probucol and similar compounds are mainly due to some other property, unrelated to their antioxidant efficacy. For example, probucol is shown to possess immunomodulatory properties. Immune reactions are known to occur during atherogenesis. We therefore tested the dimer of N-acetylcysteine, DiNAC, which is a disulfide with immunomodulating properties and enhances oxazolone-induced contact sensitivity (CS) reactions in mice, for effects on atherosclerosis. When given to male heritable hyperlipidemic rabbit (WHHL) rabbits from 10 to 22 weeks of age, this compound reduced by 50% thoracic aorta atherosclerosis (p < 0.05), without affecting plasma lipid levels. Here we also show that probucol and a close chemical analog, both known to prevent atherosclerosis in WHHL rabbits, enhance the CS reaction in mice, while two other related antioxidants did not affect the CS reaction. At least one of these is also without effect on atherosclerosis in WHHL rabbits. The results show that DiNAC might represent a new treatment modality for atherosclerosis-related disease, and suggest that some antioxidants may have antiatherosclerotic properties more related to "immunomodulatory" properties than to antioxidant properties in general.

The endogenous adjuvant squalene can induce a chronic T-cell-mediated arthritis in rats.

Squalene is a cholesterol precursor, which stimulates the immune system nonspecifically. We demonstrate that one intradermal injection of this adjuvant lipid can induce joint-specific inflammation in arthritis-prone DA rats. Histopathological and immunohistochemical analyses revealed erosion of bone and cartilage, and that development of polyarthritis coincided with infiltration of alphabeta(+) T cells. Depletion of these cells with anti-alphabeta TcR monoclonal antibody (R73) resulted in complete recovery, whereas anti-CD8 and anti-gammadelta TcR injections were ineffective. The apparent dependence on CD4(+) T cells suggested a role for genes within the major histocompatibility complex (MHC), and this was concluded from comparative studies of MHC congenic rat strains, in which DA.1H rats were less susceptible than DA rats. Furthermore, LEW.1AV1 and PVG.1AV1 rats with MHC identical to DA rats were arthritis-resistant, demonstrating that non-MHC genes also determine susceptibility. Some of these genetic influences could be linked to previously described arthritis susceptibility loci in an F2 intercross between DA and LEW.1AV1 rats (ie, Cia3, Oia2 and Cia5). Interestingly, some F2 hybrid rats developed chronic arthritis, a phenotype not apparent in the parental inbred strains. Our demonstration that an autoadjuvant can trigger chronic, immune-mediated joint-specific inflammation may give clues to the pathogenesis of rheumatoid arthritis, and it raises new questions concerning the role of endogenous molecules with adjuvant properties in chronic inflammatory diseases.

CD8+ cells suppress oil-induced arthritis.

Oil-induced arthritis is a genetically restricted polyarthritis that develops in the DA rat after injection of the mineral oil Freund's incomplete adjuvant. Here, we investigated the role of the potentially disease-limiting cell populations CD8+ T cells, gammadelta T cells, natural killer (NK) cells and NK T cells in inguinal lymph nodes for the development of this adjuvant-induced arthritis. Flow cytometry analysis before and at disease onset revealed a higher proportion of lymph node T cells expressing NKR-P1 in the disease-resistant LEW.1AV1 compared with the disease-susceptible DA strain, suggesting that NK T cells might be disease protective. However, prophylactic in vivo administration of an anti-NKR-P1 MoAb (clone 10/78) did not consistently affect the disease course. The proportion of CD8+ T cells and the ratio CD4+/CD8+ T cells in inguinal lymph nodes did not differ significantly between DA and LEW.1AV1 rats before or at disease onset. Nevertheless, prophylactic in vivo depletion of CD8+ cells by the OX8 MoAb in the DA strain resulted in an earlier disease onset compared with the control group, demonstrating that CD8+ cells regulate arthritis development. In vivo depletion of gammadelta T cells by the V65 MoAb did not alter the disease course, indicating that the disease-suppressive CD8+ cells are alphabeta T cells or NK cells.

Apoptosis in relation to proliferating cell nuclear antigen and Dukes' stage in colorectal adenocarcinoma.

Colorectal cancer is a disease that is associated with default in the balance of apoptotic regulation. In the present study apoptosis was examined in 158 colorectal adenocarcinomas using the terminal deoxynucleotidyl transferase mediated digoxigenin nick end labeling (TUNEL) method. The median apoptotic index (AI) was 0.95% (range 0-6. 68%). Eighty-two tumours exhibited AI 0.95%. We revealed a positive correlation between apoptosis and proliferation determined as the expression of proliferating cell nuclear antigen (PCNA, p=0.002). The frequency of apoptosis increased from Dukes' stage A, B, C to D (p=0.01). No correlations were found between apoptosis and the patients' sex, age, tumour location, growth pattern, differentiation, prognosis, bcl-2, p53 or K-ras. Our findings suggest that we should further investigate the relationship between apoptosis and cellular proliferative activity in colorectal cancer to evaluate whether this might provide additional information in the selection of patients for effective adjuvant therapy.

N,N'-Diacetyl-L-cystine-the disulfide dimer of N-acetylcysteine-is a potent modulator of contact sensitivity/delayed type hypersensitivity reactions in rodents.

Oral N-acetyl-L-cysteine (NAC) is used clinically for treatment of chronic obstructive pulmonary disease. NAC is easily oxidized to its disulfide. We show here that N,N'-diacetyl-L-cystine (DiNAC) is a potent modulator of contact sensitivity (CS)/delayed type hypersensitivity (DTH) reactions in rodents. Oral treatment of BALB/c mice with 0.003 to 30 micromol/kg DiNAC leads to enhancement of a CS reaction to oxazolone; DiNAC is 100 to 1000 times more potent than NAC in this respect, indicating that it does not act as a prodrug of NAC. Structure-activity studies suggest that a stereochemically-defined disulfide element is needed for activity. The DiNAC-induced enhancement of the CS reaction is counteracted by simultaneous NAC-treatment; in contrast, the CS reaction is even more enhanced in animals treated with DiNAC together with the glutathione-depleting agent buthionine sulfoximine. These data suggest that DiNAC acts via redox processes. Immunohistochemically, ear specimens from oxazolone-sensitized and -challenged BALB/c mice treated with DiNAC display increased numbers of CD8(+) cells. DiNAC treatment augments the CS reaction also when fluorescein isothiocyanate is used as a sensitizer in BALB/c mice; this is a purported TH2 type of response. However, when dinitrofluorobenzene is used as a sensitizer, inducing a purported TH1 type of response, DiNAC treatment reduces the reaction. Treatment with DiNAC also reduces a DTH footpad-swelling reaction to methylated BSA. Collectively, these data indicate that DiNAC in vivo acts as a potent and effective immunomodulator that can either enhance or reduce the CS or DTH response depending on the experimental conditions.

The effect of ambient temperature and saline loading on changes in plasma and urine electrolytes (Na+ and K+) following exercise.

In this study 4 Standardbred geldings (age 3-8 years, weight 431-531 kg) were used. The horses were fed a hay and oat diet and the total sodium intake was about 32 mg/kg bwt (690 mmol/day). An exercise test (ET) which contained 3 phases was performed. Phase I consisted of 23.5 min of mainly submaximal exercise, Phase 2 of 2 h of box rest and Phase 3 of 26 min of exercise including an intensive trot over 2600 m at 90% of VO2max. The ET was repeated 3 times: the first at 20 degrees C (30-40% RH), the second at 35 degrees C (30-40% RH) and the third at 35 degrees C (30-40% RH) after a nasogastric administration of 10 litres of 0.9% NaCl solution (35 degrees C and saline load [+ F]). Blood samples were taken before, during and after exercise. To measure fluid loss, horses were weighted before and after the ETs. Total urine output was determined 2 days before the ET (control), throughout the exercise day and for 2 days after (recovery days). There were an increase in blood and rectal temperatures after both exercise phases and a significant higher blood temperature was observed after exercise at 35 degrees C compared to 20 degrees C. The horses lost about 2% of their bodyweight (bwt) during the ETs. The plasma protein concentration increased during the exercise phases and remained elevated 2 h after exercise at both 20 degrees C and 35 degrees C, even though the horses had free access to water. The plasma protein concentration had returned to pre-exercise levels 26 h post exercise. After the saline load, total plasma protein concentration fell and increased only at the end of each exercise phase. The major mechanism regulating fluid balance after exercise seemed to be a lowered urinary excretion since water intake did not increase significantly. Urinary potassium excretion was positive throughout the experiment. During control days there was a positive sodium balance, shown by a urinary sodium excretion of 260 mmol/day. Post exercise urinary sodium excretion fell and remained very low until the second day of recovery, except after saline loading. In addition, plasma sodium was lowered 26 h after exercise at 35 degrees C. This study shows that with a daily salt intake of 38 g it will take several days to compensate for a sodium loss caused by sweating. Therefore, it is recommended that extra salt be given during the exercise day. In the experimental situation, pre-exercise saline supplementation was beneficial since the recovery time was shortened.

Effects of a postnatal exposure to cigarette smoke on hypothalamic catecholamine nerve terminal systems and on neuroendocrine function in the postnatal and adult male rat. Evidence for long-term modulation of anterior pituitary function.

The purpose of this paper was to study the possible long-term effects of postnatal exposure to cigarette smoke. Male Sprague-Dawley rats were exposed to the smoke from 2 cigarettes (Kentucky reference IR-1 type) every morning from day 1 after birth for a period of 5, 10 or 20 days. The rats were decapitated 24 hours (5, 10 and 20 days of exposure), 1 week (20 days of exposure) or 7 months (20 days of exposure) after the last exposure. Using the Falck-Hillarp methodology in combination with quantitative histofluorimetry catecholamine levels and changes in catecholamine utilization (alpha MT-induced CA fluorescence disappearance) in discrete hypothalamic catecholamine nerve terminal systems were analysed. Serum prolactin, LH, TSH and corticosterone levels were determined by means of radioimmunoassay procedures. In the postnatal period serum LH levels were significantly increased 24 hours after a 10 and 20 day exposure to cigarette smoke. In adult life after a 20-day postnatal exposure to cigarette smoke a highly significant increase was observed in serum prolactin levels, which were unaltered by this exposure when measured in the postnatal period. Twenty-four hours following a 20-day postnatal exposure, catecholamine utilization was increased in the medial palisade zone of the median eminence and substantially reduced in the parvocellular and magnocellular parts of the paraventricular hypothalamic nucleus. One week and 7 months following a 20-day postnatal exposure to cigarette smoke no alterations were observed in catecholamine levels or utilization in various hypothalamic areas including the median eminence. All the above changes were observed in the presence of an unaltered development of body weight. The results indicate that marked but temporary increases in LH secretion occur 24 hours after a postnatal exposure to cigarette smoke, while increase in prolactin secretion only develop in adult life, when the maturational processes of the brain and/or the anterior pituitary gland are completed. Changes in catecholamine levels and utilization are found in discrete hypothalamic nerve terminal networks but do not play a major role in mediating the above changes in anterior pituitary function and are probably the result of a withdrawal phenomenon.

Effects of withdrawal from chronic exposure to cigarette smoke on hypothalamic and preoptic catecholamine nerve terminal systems and on the secretion of pituitary hormones in the male rat.

A 48 h but not a 72 h or 7 day withdrawal from chronic exposure to cigarette smoke was associated with increased noradrenaline levels (quantitative histofluorimetry) in the subependymal layer (SEL) of the median eminence, the anterior periventricular hypothalamic region (PV I) and the parvocellular part of the hypothalamic nucleus (PA FP) and an increased noradrenaline utilization (tyrosine hydroxylase inhibition by alpha MT) in the SEL and the PV I. Following a 48 h or 72 h but not a 7 day withdrawal from chronic exposure to cigarette smoke an increased catecholamine utilization was found in the medial palisade zone (MPZ) of the median eminence. Reduced serum prolactin, FSH and corticosterone levels were found following a 48 h withdrawal from chronic exposure to cigarette smoke. Following a 72 h withdrawal from chronic exposure to cigarette smoke a reduced concentration of serum prolactin was noted. Chronic exposure to cigarette smoke reduced serum TSH levels and lead to a tolerance development with regard to noradrenaline levels and utilization within the preoptic region with the exception of the periventricular preoptic region. The finding of special interest in the present study is the demonstration of a highly significant lowering of corticosterone serum levels despite maintained blood levels of ACTH as seen 48 h following withdrawal. It is suggested that this type of endocrine change may lead to changes in fear-motivated behaviour and contribute to behavioural withdrawal reactions. The maintained reductions of serum prolactin levels found after 48 h and 72 h of withdrawal from cigarette smoke exposure (cf. Andersson et al. 1985a) is discussed in terms of an increased catecholamine utilization in the medial palisade zone of the median eminance. This activation is suggested to be caused by the development of a prolactin receptor supersensitivity within the medium eminence. The present evidence indicates withdrawal effects mainly in the noradrenaline nerve terminals of the subependymal layer of the median eminence, the anterior periventricular hypothalamic region and the parvocellular part of the paraventricular hypothalamic nucleus which inter alia are involved in regulation of ACTH secretion (cf. Andersson et al. 1985a).

The district nurse and the district physician in health care teams. An analysis of the content of primary health care.

An assessment of community nursing in relation to physician care has been made in a Swedish primary care district. The staff was organized in health care teams. A totally integrated, comprehensive care service for everyone in the geographically defined district was made possible, as all members of the team used the same medical records. Visits in district care (district nurse, practical nurse) amounted to more than 50% of the visits to the teams. The visiting pattern in district care was dominated by the young and the old, the ages below 5 years of age making 3.7 visits per year, and the ages above 75 years making 10.0 visits. Health care was an important task among the children, while chronic ulcer of skin, senile dementia and diabetes were the most common diagnoses among the elderly. Every third visit in district care was a home visit. In almost 50% of the visits no appointment had been made in advance, which demonstrates a high accessibility to the district nurse. The distribution of diagnoses presented several social problems. Diagnoses like neuroses, alcoholism, and senile dementia produced many visits by few patients. Compared to physician visits, the district nurse made more home visits, had more visits among the young and the old, and had a different distribution of diagnoses. Regardless of, or despite, their different ways of working, the district nurse and the district physician complemented each other in the team co-operation. Besides her role as a health professional concerned about health care and medical treatment, the district nurse is an important social contact for many individuals living in her district.