The effect of calcitonin gene-related peptide (CGRP) on human forearm blood flow

Is calcitonin gene-related peptide a modulator of menopausal vasomotor symptoms?

PURPOSE

Calcitonin gene-related peptide (CGRP) is a neuropeptide widely distributed in the central and peripheral nervous systems, which is known as a potent vasodilator. Postmenopausal women who experience hot flushes have high levels of plasma CGRP, suggesting its involvement in menopausal vasomotor symptoms.

METHODS

In this review, we describe the biochemical aspects of CGRP and its effects associated with deficiencies of sexual hormones on skin temperature, vasodilatation, and sweating as well as the possible peripheral and central mechanisms involved in these events.

RESULTS

Several studies have shown that the effects of CGRP on increasing skin temperature and inducing vasodilatation are potentiated by a deficiency of sex hormones, a common condition of postmenopausal women. Additionally, the medial preoptic area of the hypothalamus, involved in thermoregulation, contains over 25-fold more CGRP-immunoreactive cells in female rodents compared with male rodents, reinforcing the role of female sex hormones on the action of CGRP. Some studies suggest that ovarian hormone deficiency decreases circulating endogenous CGRP, inducing an upregulation of CGRP receptors. Consequently, the high CGRP receptor density, especially in blood vessels, amplifies the stimulatory effects of this neuropeptide to raise skin temperature in postmenopausal women during hot flushes.

CONCLUSIONS

The duration of the perception of each hot flush in a woman is brief, while local reddening after intradermal administration of α-CGRP persists for 1 to 6 h. This contrast remains unclear.

CGRP Is Critical for Hot Flushes in Ovariectomized Mice

Hot flushes are common and troublesome symptoms of menopause. The neuropeptide calcitonin gene-related peptide (CGRP) is increased in plasma during hot flushes but it has not been clear if CGRP is causally involved in the mechanism underpinning the flushes. Here, we examined the effect of interventions with CGRP in a mouse model of hot flushes based on flush-like temperature increases triggered by forced physical activity in ovariectomized mice. Compared to normal mice, ovariectomized mice reacted with an exaggerated, flush-like, temperature increase after physical exercise. This increase was completely blocked by the non-peptide CGRP-antagonist MK-8825 (-0.41 degrees Celsius, 95% CI: -0,83 to 0,012, p < 0.0001) at a dose that had no obvious effects on locomotor activity (50 mg/kg). Further, the flush-like temperature increases were strongly attenuated in ovariectomized mice lacking αCGRP due to a genetic modification. Collectively, our findings suggest that CGRP is an important mediator of experimentally induced hot flushes and they identify CGRP antagonists as promising treatment candidates for women and possibly also men with hot flushes.

Changes in sympathetic neurovascular function following spinal cord injury

The effects of spinal cord injury (SCI) on sympathetic neurovascular transmission have generally been ignored. This review describes changes in sympathetic nerve-mediated activation of arterial vessels to which ongoing sympathetic activity has been reduced or silenced following spinal cord transection in rats. In all vessels studied in rats, SCI markedly enhanced their contractile responses to nerve activity. However, the mechanisms that augment neurovascular transmission differ between the rat tail artery and mesenteric artery. In tail artery, the enhancement of neurovascular transmission cannot be attributed to changes in sensitivity of the vascular muscle to α₁- or α₂-adrenoceptor agonists. Instead the contribution of L-type Ca²⁺ channels to activation of the smooth muscle by nerve-released noradrenaline is greatly increased following SCI. By contrast, mesenteric arteries from SCI rats had increased sensitivity to phenylephrine but not to methoxamine. While both phenylephrine and methoxamine are α₁-adrenoceptor agonists, only phenylephrine is a substrate for the neuronal noradrenaline transporter. Therefore the selective increase in sensitivity to phenylephrine suggests that the activity of the neuronal noradrenaline transporter is reduced. While present evidence suggests that sympathetic vasoconstrictor neurons do not contribute to the normal regulation of peripheral resistance below a complete SCI in humans, the available evidence does indicate that these experimental findings in animals are likely to apply after SCI in humans and contribute to autonomic dysreflexia.

Hot flushes in healthy aging men differ from those in men with prostate cancer and in menopausal women

Calcitonin gene-related peptide (CGRP) seems to be involved in hot flushes in women and in castrated men. Therefore, we studied whether the plasma concentrations of CGRP changed during flushes in a group of healthy aging men. Twelve men (49-71 years) with no history of current or former prostate cancer or hormonal treatment reporting ≥ 20 flushes/week were investigated. Blood samples were drawn during and between flushes for analysis of CGRP and also androgen concentrations, that is, testosterone and bioavailable testosterone were analysed. Skin temperature and skin conductance were monitored. Thirty-five flushes were reported by 10 men. The plasma concentrations of CGRP did not increase during flushes. No significant change in skin temperature or conductance was found. CGRP is probably not involved in the mechanisms of flushes in healthy aging men. Therefore, flushes in aging healthy men seem to be different from flushes in men and women deprived of sex steroids where CGRP increases during flushes.

Acupuncture as treatment of hot flashes and the possible role of calcitonin gene-related Peptide

The mechanisms behind hot flashes in menopausal women are not fully understood. The flashes in women are probably preceded by and actually initiated by a sudden downward shift in the set point for the core body temperature in the thermoregulatory center that is affected by sex steroids, β-endorphins, and other central neurotransmitters. Treatments that influence these factors may be expected to reduce hot flashes. Since therapy with sex steroids for hot flashes has appeared to cause a number of side effects and risks and women with hot flashes and breast cancer as well as men with prostate cancer and hot flashes are prevented from sex steroid therapy there is a great need for alternative therapies. Acupuncture affecting the opioid system has been suggested as an alternative treatment option for hot flashes in menopausal women and castrated men. The heat loss during hot flashes may be mediated by the potent vasodilator and sweat gland activator calcitonin gene-related peptide (CGRP) the concentration of which increases in plasma during flashes in menopausal women and, according to one study, in castrated men with flushes. There is also evidence for connections between the opioid system and the release of CGRP. In this paper we discuss acupuncture as a treatment alternative for hot flashes and the role of CGRP in this context.

Acupuncture for hot flashes in patients with prostate cancer

OBJECTIVES

To determine the effect of acupuncture on hot flash frequency and intensity, quality of life, and sleep quality in patients undergoing hormonal therapy for prostate cancer. Hot flashes are a common adverse effect of hormonal therapy for prostate cancer.

METHODS

Men who had a hot flash score > 4 who were receiving androgen deprivation therapy for prostate cancer underwent acupuncture with electrostimulation biweekly for 4 weeks, then weekly for 6 weeks, using a predefined treatment plan. The primary endpoint was a 50% reduction in the hot flash score after 4 weeks of therapy, calculated from the patients' daily hot flash diaries. The hot flash-related quality of life and sleep quality and biomarkers potentially related to hot flashes, including serotonin, calcitonin gene-related peptide, and urinary 5-hydroxyindoleacetic acid, were examined.

RESULTS

A total of 25 men were enrolled from September 2003 to April 2007. Of these, 22 were eligible and evaluable. After 4 weeks, 9 (41%, 95% confidence interval 21%-64%) of 22 patients had had a > 50% reduction in the hot flash score. Of the 22 patients, 12 (55%, 95% confidence interval 32%-76%) met this response definition at any point during the therapy course. No patient had a significant increase in hot flash score during therapy. A reduced hot flash score was associated with improvement in the hot flash-related quality of life and sleep quality.

CONCLUSIONS

Multiple placebo-controlled trials have demonstrated a 25% response rate to placebo treatment for hot flashes. Of the 22 patients, 41% had responded by week 4 and 55% overall in the present pilot study, providing evidence of a potentially meaningful benefit. Additional studies of acupuncture for hot flashes in this population are warranted.

Managing hot flushes in men after prostate cancer--a systematic review

CONTEXT AND OBJECTIVE

The aim of this study was to describe hot flushes in men with prostate cancer, and their treatment methods.

METHOD

A systematic review was conducted of the literature indexed between 1966 and 2009 on the MEDLINE, the ISI Web of Knowledge, Cinahl and PsycINFO. Of 252 articles identified, 32 were selected for consideration of their complete texts, of which five were subject to detailed analysis.

RESULTS

Diethylstilbestrol, megestrol acetate and cyproterone acetate have the strongest effect, giving a 75% or larger decrease of the number of hot flushes, but they may have severe or bothersome side-effects. Gabapentin has an uncertain effect. Clonidine is not proven effective for hot flushes. Long-term effects were not evaluated in any of the studies. SSRI/SNRI and acupuncture may have a moderate effect on hot flushes but are not proven in any RCTs.

CONCLUSION

Hot flushes are common and bothersome symptoms in men with prostate cancer and those taking anti-androgen treatment, and reduce quality of life. Few treatments are available and some are avoided for these patients. Additional prospective treatment studies are needed, with long-term follow-up, in order to evaluate the effects and risks of treatments. Treatments with few or no severe side-effects should be prioritised in future investigations. Experimental studies are also needed to elucidate the mechanism behind hot flushes in men and to suggest routes for the development of new treatments.

Calcitonin gene-related peptide, adrenomedullin and flushing

Administration of calcitonin gene-related peptide (CGRP) or adrenomedullin (AM) can cause facial flushing, suggesting that the peptides may be important in hot flushes experienced particularly by post-menopausal women. Five studies have measured plasma CGRP concentrations in post-menopausal women who suffer from flushes; all demonstrated elevations of between 170% and 320% over control. Three of the studies showed a temporal relationship between flushes and CGRP elevation. A further study has shown that CGRP is elevated in the urine of women who suffer from flushes. Only a single study has investigated flushes in pre-menopausal women; no elevation of CGRP was observed. Flushes are also experienced by men undergoing androgen deprivation therapy. Whilst one study failed to find any increase in CGRP in the urine of these individuals, a small study has identified an increase in plasma CGRP. No studies have investigated plasma AM or the related peptide, intermedin/AM2. Overall, there is good evidence to show that flushes in post-menopausal women are accompanied by an increase in CGRP. CGRP could act centrally on the thermoregulatory centre of the hypothalamus as well as peripherally to cause vasodilation and sweating. However, it remains to be demonstrated that the elevated CGRP causes flushes. Recently developed CGRP antagonists provide an opportunity to test this hypothesis. If they are successful, they may represent a useful alternative to oestrogen replacement therapy.

Cholinergic mechanisms of cutaneous active vasodilation during heat stress in cystic fibrosis

To test the hypothesis that cutaneous active vasodilation in heat stress is mediated by a redundant cholinergic cotransmitter system, we examined the effects of atropine on skin blood flow (SkBF) increases during heat stress in persons with (CF) and without cystic fibrosis (non-CF). Vasoactive intestinal peptide (VIP) has been implicated as a mediator of cutaneous vasodilation in heat stress. VIP-containing cutaneous neurons are sparse in CF, yet SkBF increases during heat stress are normal. In CF, augmented ACh release or muscarinic receptor sensitivity could compensate for decreased VIP; if so, active vasodilation would be attenuated by atropine in CF relative to non-CF. Atropine was administered into skin by iontophoresis in seven CF and seven matched non-CF subjects. SkBF was monitored by laser-Doppler flowmetry (LDF) at atropine treated and untreated sites. Blood pressure [mean arterial pressure (MAP)] was monitored (Finapres), and cutaneous vascular conductance was calculated (CVC = LDF/MAP). The protocol began with a normothermic period followed by a 3-min cold stress and 30-45 min of heat stress. Finally, LDF sites were warmed to 42 degrees C to effect maximal vasodilation. CVC was normalized to its site-specific maximum. During heat stress, CVC increased in both CF and non-CF (P < 0.01). CVC increases were attenuated by atropine in both groups (P < 0.01); however, the responses did not differ between groups (P = 0.99). We conclude that in CF there is not greater dependence on redundant cholinergic mechanisms for cutaneous active vasodilation than in non-CF.

Reproducibility of forearm vasodilator response to intra-arterial infusion of calcitonin gene-related peptide assessed by venous occlusion plethysmography

AIMS

To assess the reproducibility of the forearm blood flow (FBF) response to intra-arterial infusion of calcitonin-gene related peptide (CGRP), measured by venous occlusion plethysmography. In addition, to compare different ways of expressing the FBF response and perform sample size calculations.

METHODS

On two separate visits, CGRP (10 ng min(-1) dl(-1) forearm) was infused for 45 min into the brachial artery of six healthy subjects. Reproducibility was assessed by calculating mean difference, repeatability coefficient, within-subject coefficient of variation (WCV) and intraclass correlation coefficient.

RESULTS

CGRP increased FBF from 2.8 +/- 0.4 and 3.2 +/- 0.7 (at baseline) to 15.4 +/- 1.4 and 15.2 +/- 1.5 ml min(-1) dl(-1) forearm (at 45 min) on visits 1 and 2, respectively (P < 0.0001 for both visits). Mean difference in FBF at 45 min between both visits was 0.3 ml min(-1) dl(-1) forearm (repeatability coefficient: 4.1 ml min(-1) dl(-1) forearm). This FBF response appeared to be more reproducible when expressed as absolute FBF in the infused arm (WCV 11%) compared with absolute FBF-ratio between both arms (WCV 37%), percentage change from baseline in FBF in the infused arm (WCV 29%) and percentage change from baseline in FBF-ratio (WCV 40%). When expressed as absolute FBF, a sample size of five (95% confidence interval: 2-12) subjects gives 90% power at a type I error probability of 0.05 to detect a 25% shift in FBF response.

CONCLUSIONS

Intra-arterial infusion of CGRP results in a forearm vasodilator response which is reproducible between days. This response is most reproducible when expressed as absolute FBF. The presented methodology provides a suitable pharmacodynamic model to assess the in vivo activity of CGRP-receptor antagonists in a small number of subjects.

Calcitonin gene-related peptide during sweating in young healthy women

Calcitonin gene-related peptide (CGRP) concentrations are increased in postmenopausal women and castrated men with symptomatic flushing. We wanted to determine if a CGRP increase exists in the plasma of healthy fertile-age women during sweating. Plasma concentrations of CGRP were measured by radioimmunoassay at maximal sweating during a sauna session and during bicycle exercise both at maximal and 70% of maximal work capacity in 8 healthy women of fertile age. Plasma concentrations of CGRP were unaffected (>90% statistical power) during both experimental sessions. We suggest that sweating itself does not explain the rise in CGRP concentrations observed in flushing postmenopausal women.

Menopausal hot flash and calciotonin gene-related peptide; effect of Keishi-bukuryo-gan, a kampo medicine, related to plasma calciotonin gene-related peptide level

OBJECTIVES

The purpose of this study is to investigate relationship of menopausal hot flash and calcitonin gene-related peptide (CGRP). Furthermore, this study evaluated the effect of the Japanese herbal (kampo) medicine Keishi-bukuryo-gan from the aspect of CGRP regulation.

METHODS

Plasma CGRP and vasoactive intestinal peptide (VIP) levels were measured during hot flash and CGRP reactivity was studied by cold load test in subjects with/without hot flashes. The effect of Keishi-bukuryo-gan was assessed in comparison with plasma CGRP level.

RESULTS

Only plasma CGRP but not VIP significantly elevated at the occurrence of hot flash (P=0.002). Stress by cold load significantly enhanced the over-secretion of CGRP in subjects with flash compared with those without flash (P=0.003) 3 min after the load. Keishi-bukuryo-gan decreased plasma CGRP level in subjects with hot flash.

CONCLUSIONS

CGRP but not VIP was mainly related to the occurrence of hot flash. Keishi-bukuryo-gan, Japanese herbal medicine, improves hot flash possibly affecting plasma CGRP level.

Effects of the vasoactive neuropeptides calcitonin gene-related peptide, substance P and vasoactive intestinal polypeptide on skin temperature in ovariectomized rats

The effects of three vasoactive neuropeptides, calcitonin gene-related peptide (CGRP), substance P (SP) and vasoactive intestinal polypeptide (VIP), on vasodilation and skin temperature were investigated in ovariectomized (OVX) and sham-operated control rats. CGRP (0.01-1 nmol), VIP (0.01-10 nmol) and SP (0.1-100 nmol) produced vasodilation in PGF(2 alpha) (10 microM)-induced contraction of mesenteric vascular beds isolated from OVX and sham-operated rats in a dose-dependent manner. Intravenous injection of CGRP (1-10 microg/kg), VIP (10-50 microg/kg) and SP (10-50 microg/kg) elevated the skin temperature in OVX and sham-operated rats in a dose-dependent manner. CGRP had the greatest effect on both parameters, followed by VIP, with the smallest effect in SP. These parallel increases of vasodilation and skin temperature with CGRP were significantly greater in OVX rats than in sham-operated rats. However, no significant differences were observed in VIP- or SP-induced vasodilation and skin temperature increases between OVX and sham-operated rats. These results suggest not only that CGRP is closely related to the elevation of skin temperature but also that CGRP-induced responses are more affected by ovarian hormone deficiency.

Complementary/alternative therapies for reducing hot flashes in prostate cancer patients: reevaluating the existing indirect data from studies of breast cancer and postmenopausal women

Vasomotor hot flashes are a common problem in women who are postmenopausal or receiving antiestrogen treatment for breast cancer. Hot flashes are also a common problem after orchiectomy/luteinizing hormone-releasing hormone therapy, occurring generally in 50% to 66% of these men. Prescribed treatments for hot flashes for men on hormonal ablation treatment for prostate cancer are well documented. These conventional agents have shown good results, but their long-term efficacy, safety, and cost are still questioned. Therefore, the search for other viable agents, including nontraditional treatments, continues. Complementary/alternative treatments to alleviate hot flashes in women have generated an enormous amount of interest. However, these options have received little attention in men with hot flashes. Research with vitamin E, soy, black cohosh, red clover, and numerous other alternative treatments in women may provide some indirect but valuable insight on their potential effectiveness in men. Many of these alternatives have been a disappointment in recent randomized trials of women, and it is likely that there will be similar results with men. However, numerous supplements have yet to be tested in a clinical trial against a placebo, and clinicians should become aware of this ever-increasing list. Patients should be made aware of the primary importance of lifestyle interventions that could partially affect hot flashes and immediately affect overall health, especially during the period of androgen suppression, when it is not uncommon to observe accelerated weight changes and insulin insensitivity. Otherwise, recent research with older and newer conventional agents, such as antidepressants or estrogen/progesterone, should be emphasized at this time for moderate-to-severe hot flashes that profoundly affect daily activities and/or sleep. Antidepressant supplements (St. John's wort) or acupuncture could also be an attractive option in future investigations. Low-dose estrogen seems particularly attractive, because it is inexpensive and may simultaneously reduce hot flashes and the risk of osteoporosis in men receiving long-term androgen suppression therapy; however, the potential for cardiovascular complications must be further investigated. Ultimately, adequate research (vs placebo) should determine the fate of the alternative supplements proposed for hot flash reduction.

Nerve distribution in hemangiomas depends on the proliferative state of the microvasculature

Hemangiomas appear at birth and undergo gradual regression within several years. Recent published studies have documented increased nerve numbers in port-wine stains and intramuscular vascular tumors. The aim of this study was to establish a relationship between angiogenesis and nerve growth in lesions that undergo neovascular proliferation followed by vessel involution. Twenty-two hemangiomas and arteriovenous malformations were studied using indirect immunocytochemistry with antibodies against the nerve markers protein gene product 9.5 (PGP 9.5) and calcitonin gene-related peptide (CGRP). Nerves and vessels were counted and compared. Our results indicate that PGP 9.5(+) and CGRP(+) nerves were most numerous in growing hemangiomas and numbers were reduced in involuting hemangiomas and vascular malformations. The percentage of CGRP(+) sensory nerves was markedly increased in growing hemangiomas (45.3%) compared with involuting hemangiomas (21.2). These data indicate that hemangiomas with increasing neovascularization have increased sensory nerve growth. Sensory nerve-derived neuropeptides are known to act as endothelial cell mitogens and may contribute to the angiogenesis in these vascular tumors. Conversely, angiogenic endothelial cells may secrete mediators that promote nerve fiber growth. These results suggest that endothelial cell proliferation and sensory nerve fiber growth may be closely related.

Postmenopausal women with vasomotor symptoms have increased urinary excretion of calcitonin gene-related peptide

OBJECTIVES

To establish whether 24 h urinary excretion of the potent vasodilator calcitonin gene-related peptide (CGRP) was higher in postmenopausal women with vasomotor symptoms compared to the level in women without symptoms. We also wanted to establish whether urinary excretion of CGRP changed during the menstrual cycle in women of fertile age.

MATERIAL AND METHODS

Thirteen postmenopausal women with and 13 women without vasomotor symptoms were included. Urine was collected over 24 h and CGRP excretion was measured utilizing radio-immunoassay technique. Twenty-four hour CGRP excretion was also measured in ten fertile women with regular cycles in early follicular, preovulatory and midluteal phase.

RESULTS

Twenty-four hour urinary excretion of CGRP was significantly higher in women with vasomotor symptoms compared to non-flushing women (median 7.16 vs 5.15 pmol/24 h; P = 0.028). CGRP concentrations were stable throughout the ovulatory cycles.

CONCLUSION

The 24 h urinary excretion of CGRP is higher in women with vasomotor symptoms than in women without these symptoms. CGRP may be the mediator of vasodilator signals originating from the thermoregulatory center.

Unilateral injection of calcitonin gene-related peptide (CGRP) induces bilateral oedema formation and release of CGRP-like immunoreactivity in the rat hindpaw

The contribution of calcitonin gene-related peptide (CGRP) to bilateral oedema formation in the rat hindpaw following an unilateral challenge with CGRP was investigated. Rats were injected into the left hindpaw with either saline, CGRP or a CGRP antagonist (CGRP8-37). All injections were given in a double blind fashion and in a volume of 100 microl. CGRP and CGRP8-37 were administered in concentrations of 75, 150 or 300 pmol. Volumes of the right and left hindpaw were measured every hour for 5 h by plethysmometry. Injection of CGRP 300 pmol into the left hindpaw resulted in a bilaterally increased hindpaw volume after 5 h as compared with the groups given saline. No changes were found in hindpaw volumes following the injection of either 75 or 150 pmol of CGRP or 75, 150 or 300 pmol of CGRP8-37 as compared with saline injection. To elucidate whether or not the bilateral oedema formation was related to a release of endogenous CGRP, microdialysis of the contralateral hindpaw was carried out, and concentrations of CGRP-like immunoreactivity (-LI) were determined by radioimmunoassay and high performance liquid chromatography. Injection of CGRP 300 pmol into the left hindpaw increased the release of CGRP-LI into the right hindpaw perfusate after 4 and 5 h. No changes in CGRP-LI were detected in the right hindpaw perfusate following challenge with saline or CGRP8-37. To study the contribution of the nervous system to the contralateral release of CGRP-LI, sciatic nerve ligated and intact sham-operated rats were used. Sciatic nerve ligation but not sham-operation on the non-injected side abolished the increased release of CGRP-LI following contralateral administration of CGRP 300 pmol. To study the spinal cord mechanisms resulting in the bilateral oedema formation following unilateral challenge with 300 pmol of CGRP, intrathecal pretreatment with either 10 nmol bicuculline (GABA(A) receptor antagonist) or 10 nmol CGRP8-37 was carried out. Bicuculline but not CGRP8-37 abolished the bilateral oedema formation induced by CGRP 300 pmol. In order to study the mechanisms by which administration of CGRP 300 pmol induces oedema, CGRP 300 pmol was administered concomitantly with either 300 pmol of CGRP8-37 (CGRP receptor antagonist), or 3 nmol of promethazine (H1 receptor antagonist), or 3 nmol of s(-)-propranolol (5-HT1 receptor antagonist), or 3 nmol of cyproheptadine (5-HT2 receptor antagonist) or 3 nmol of ICS 205-930 (5-HT3 receptor antagonist). Oedema formation was measured at 1, 5, 7 and 24 h. Injection of CGRP 300 pmol into the left hindpaw induced a bilateral oedema formation which was still significant at 24 h. Concomitant administration of either CGRP8-37, ICS 205-920 or cyproheptadine blocked the oedema formation at 24 h. No effect on oedema formation was found when CGRP 300 pmol was co-administered with either promethazine or s(-)-propranolol (H1 and 5-HT1 receptor antagonists, respectively). The results of the present study show that both the nervous system and local inflammatory processes contribute to bilateral hindpaw oedema formation following unilateral challenge with CGRP 300 pmol. Our results indicate that endogenous release of CGRP following inflammatory response may play an important role in inducing oedema formation.

Physical exercise and vasomotor symptoms in postmenopausal women

BACKGROUND

The mechanisms causing postmenopausal vasomotor symptoms are unknown, but changes in hypothalamic beta-endorphins have been suggested to be involved. beta-endorphin production may be increased by regular physical exercise.

OBJECTIVE

To assess if physically active women suffered from vasomotor symptoms to a lower extent than sedentary women.

MATERIAL AND METHODS

All women (n = 1323) in the ages ranging from 55-56 years in the community of Linköping Sweden, were included. In a questionnaire these women were asked about their physical exercise habits and their complaints from vasomotor symptoms. Only those 793 women who had reached a natural menopause were grouped into sedentary, moderately or highly active women, based on a physical activity score.

RESULTS

Only 5% of highly physically active women experienced severe hot flushes as compared with 14-16% of women who had little or no weekly exercise (P < 0.05; relative risk 0.26; CI 95%: 0.10-0.71). This was not explained by differences in body mass index, smoking habits or use of hormone replacement therapy. Women who used hormone replacement therapy were more physically active than non-users (P < 0.05).

CONCLUSION

Fewer physically active women had severe vasomotor symptoms compared with sedentary women. This may be due to a selection bias but also to the fact that physical exercise on a regular basis affects neurotransmitters which regulate central thermoregulation.

Effects of physical activity and acupuncture on calcitonin gene-related peptide immunoreactivity in different parts of the rat brain and in cerebrospinal fluid, serum and urine

Calcitonin gene-related peptide (CGRP) is a very potent vasodilator in the nervous system, and may be involved in hot flushes experienced by most women around menopause. Flushing post-menopausal women had higher urinary excretion of CGRP before than after successful treatment of their flushes with acupuncture. The prevalence of vasomotor symptoms is lower in physically active women. In a rat model we therefore intended to assess whether acupuncture and exercise affected CGRP concentrations in different parts of the brain and peripherally. The aim of the study was to elucidate the short- and long-term effects of exercise and acupuncture on CGRP concentrations in the nervous system of normal adult rats. In a rat model, we examined the effects of single interventions and long-term treatment with physical exercise and manual or electro-acupuncture on CGRP concentrations in urine, cerebrospinal fluid and serum and different parts of the brain. In all compartments studied, but significantly only in the cerebrospinal fluid, CGRP increased after a single session of physical exercise or electro-acupuncture. Manual acupuncture did not change CGRP concentrations in any compartment. Rats had the highest concentrations of CGRP in the pituitary and hypothalamus but the concentrations did not differ significantly between control rats and those subjected to long-term treatment with manual or electro-acupuncture or running rats. Rats treated with electro-acupuncture had twice the CGRP concentration in the frontal cortex compared to control rats, albeit the difference did not reach statistical significance. Evidently manual and electro-acupuncture have different effects, whereas electro-acupuncture and physical exercise have more similar effects on CGRP production and/or release. To elucidate the role of CGRP in vasomotor symptoms, further studies with older flushing rats should be performed.

Evaluation of skin blood flow by laser Doppler flowmetry

Laser Doppler flowmetry is an excellent noninvasive technique for the measurement of cutaneous microcirculation. The list of applications of laser Doppler flowmetry in dermatology is long. It can be applied to monitor inflammation caused by various drugs, chemicals, and allergens related to blood flow. To measure certain inflammatory reactions a combination of other bioengineering measurements is desirable. Flaps can be monitored, and burn depth measured by laser Doppler flowmetry. Through blood flow measurement, the pathophysiology of various skin diseases can be verified and certain treatments can be partially monitored. Although it is not as directly applicable to daily clinical practice, except in a few cases, laser Doppler flowmetry is a very useful technique in various kinds of dermatologic research.

Maffucci's syndrome--the result of neural abnormalities? Evidence of mitogenic neurotransmitters present in enchondromas and soft tissue hemangiomas

BACKGROUND

Maffucci's syndrome (MS) is distinguished by the enigmatic association of benign cartilaginous bone tumors and soft tissue hemangiomas.

METHODS

This study was conducted to define the distribution of nerves and neuropeptides around these tumors. Results were measured by quantitative image analysis of immunohistochemical staining. Four types of tissues were compared: connective tissues around normal muscles, solitary hemangiomas, MS hemangiomas, and MS enchondromas (the last two from a single patient).

RESULTS

The number of nerves was found to be quadrupled in both types of hemangiomas as compared to normal connective tissue. A unique feature of MS tissues is the presence of an increased number of nerve fibers not only in the lesions but also in histologically normal margins of resection surrounding the lesions. Furthermore, hemangiomas of both types were found to contain a significantly higher number of calcitonin gene-related peptide-, substance P-, and methionine enkephalin-positive fibers than did normal muscle or its related fibroconnective tissue. These neuropeptides are mitogens, and their presence stimulates the growth of the abnormal blood vessels. Enchondroma fragments from an MS patient contained numerous methionine enkephalin-positive nerves. This neuropeptide is known to act as a growth factor in cartilage proliferation.

CONCLUSIONS

A neural abnormality of the neuropeptidergic nervous system seems to relate to the abnormal tumors seen in MS.

Sensory nerve terminal activity in severe hypertension as reflected by circulating calcitonin gene-related peptide (CGRP) and substance P

In patients with severe hypertension and in age and sex matched controls the circulating levels of calcitonin gene-related peptide-like immunoreactivity (CGRP-LI) and substance P-LI were measured. Samples were taken before medication, after 2-4 weeks and 2-12 months of pharmacological treatment to normotension. In the control group CGRP-LI levels were significantly higher for females than for males. No such relation was seen for substance P-LI. There were no correlations between CGRP-LI, substance P-LI or blood pressure. In the untreated acute hypertensive group there was a significant correlation between circulating levels of CGRP-LI and both diastolic and systolic blood pressure. No such relationship was seen for substance P-LI. The plasma levels of substance P-LI were significantly elevated (2.8 +/- 4.0) compared to controls (1.3 +/- 1.3, pmol/l, mean +/- S.D., p < 0.01). The levels of CGRP-LI did not differ from the control group. After 2-4 weeks of treatment the blood pressure decreased significantly and the plasma levels of substance P-LI were normalized while the CGRP-LI still did not differ from that of controls. After 2-12 months of treatment the blood pressure was still normalized, and the plasma levels of CGRP-LI and substance P-LI were not different from the control group. In the present study there was a positive correlation in hypertensives between the circulating CGRP-LI levels and diastolic and systolic blood pressure and elevated levels of substance P-LI. This would implicate the existence of a dynamic control through which the sensory system may register and damp the pressure response.

Neuropeptidergic innervation of intramuscular hemangiomas

Intramuscular hemangiomas are idiopathic lesions which are either tumoral or developmental in origin. A close association of abnormal blood vessels with nerve fibers is found and may suggest that nerves have a primary inciting role in the development of these lesions. In the current study, the number of nerve fibers in different zones around the tumors, as well as the type of neuropeptides present in these fibers, was quantitatively assessed by computer-assisted image analysis of immunohistochemical staining of histological slides. The number of nerve fibers as determined by positive staining by anti-protein S-100 antibodies was found to be elevated in the immediate vicinity of the abnormal blood vessels. The density of the nerve fibers rapidly declined with increasing distance from the hemangiomas, reaching normal values at distances of over 2 mm. Furthermore, hemangiomas contain a significantly higher number of calcitonin gene-related peptide (CGRP), substance P, and Met-enkephalin-positive fibers. The most significant rise in number is that of CGRP-positive fibers. This neuropeptide is a known mitogen, which could be responsible for the growth of the hemangiomatous blood vessels. Substance P is a nociceptive neurotransmitter and its presence can explain the pain which often accompanies even tiny intramuscular hemangiomas.