ode45 for loop stuck at 1st loop

I'm trying to solve an ode45 for 130 different values of ABP (a parameter in the equations), hence I decided to make a for loop around the solver but the solver is stuck in the first value of ABP (ABP(i)=40, i=1) Could you please tell me how to make it shift to i=2, hence ABP=41 ? Here's the full code so you can see what's happening by running it.

    clear all 
    clc

    %%=========== ODE45 ==================

    ABP= linspace(40,170,131)  %arterial pressure 

       for i=1:1:length(ABP) %change in ABP at every time step

           sol = ode45(@first,[0 100], [0 0 0 0 0.205 97.6 12 49.67],[],ABP(i)); %(function, timespan, initial condition for xq,xc,xm,xm1,Ca,P1,V_sa,P2  ; options ; call new value of ABP)

        end

    %%========= FUNCTION ==================
    function dvdt = first(t,v,ABP)

    xq= v(1);
    xc= v(2);
    xm= v(3);
    xm1= v(4);
    Ca=v(5);
    P1= v(6);
    V_sa= v(7);
    P2 = v(8);

    % -----Constants -----
    R_la= 0.4;
    R_sa_b= 5.03;
    R_sv= 1.32;
    R_lv= 0.56;
    P_v= 6;
    V_la=1;
    V_sa_b= 12;
    P_ic= 10;
    k_ven= 0.186;
    P_v1= -2.25;
    V_vn= 28; 
    tau_q= 20; 
    Pa_co2_b= 40; 
    tau_co2= 40; 
    tau1= 2; 
    tau2= 4;
    tau_g= 1; 
    C_a_p=2.87; 
    C_a_n= 0.164;
    g=0.2; 
    E=0.4; 
    K= 0.15; 
    V0= 0.02; 
    q_b=12.5;
    G_q=3; 
    Pa_co2=40; 
    Ca_b= 0.205;
    eps=1;
    u=0.5; 
    Pa_b=100;
    ka=3.68;

    deltaCa_p=2.87;
    deltaCa_n=0.164; 

    % =========== System of diff eq =========================================
    dxq= (-xq+G_q*( ( (P1- P2)/(R_sv+0.5*(R_sa_b/(V_sa/V_sa_b)^2))) -q_b /q_b))/tau_q;
    dxc=(-xc +0.3+3*tanh((Pa_co2/Pa_co2_b) -1.1))/tau_co2;
    dxm=(eps*u-tau2*xm1-xm)/tau1^2;
    dxm1=xm1;

    sum_xqxcxm=xm+xc-xq %sum of feedback mechanisms

    %----- AMPLITUDE OF COMPLIANCE -----
    if (ABP==40) 
        delta=deltaCa_n; %because sum_xqxcxm <0 for ABP=40
    elseif (ABP==41)
        delta=deltaCa_n;
    end

    %----- ARTERIAL COMPLIANCE ----- 
    if ABP==100 %baseline condition
        Ca=Ca_b
    elseif (ABP<100)
        Ca= Ca_b+0.5*delta*tanh(2*sum_xqxcxm/delta)

    elseif(ABP>100)
        Ca= Ca_b+0.5*delta*tanh(2*sum_xqxcxm/delta)
    end

    dCa=0.5*delta*(1- ((cosh(4*(xm+xc-xq)/delta))-1)/(cosh(4*(xm+xc-xq)) +1));
    dP1= 1/Ca * ((ABP-P1)/(R_la+0.5*(R_sa_b/(V_sa/V_sa_b)^2)) - (P1-P2)/(R_sv+0.5*(R_sa_b/(V_sa/V_sa_b)^2)) -dCa*(P1-P_ic));
    dV_sa= dCa*(P1-P_ic) + Ca*dP1;
    dP2=1/(1/(k_ven*(P2-P_ic-P_v1)))*((P1-P2)/(R_sv+0.5*(R_sa_b/(V_sa/V_sa_b)^2)) -(P2-P_v)/R_lv);

    dvdt=[dxq;dxc;dxm;dxm1;dCa;dP1;dV_sa;dP2]

    %Calculate CBF
    Rsa= R_sa_b*(V_sa_b/V_sa)^2;
    CBF= (P1 -P2)/(Rsa*0.5 + R_sv);

    figure(1)
    xlabel('ABP')
    ylabel('CBF')
    title('Cerebral blood flow dependence on arterial blood pressure')
    plot(ABP,CBF)
    hold on

    end

[Torsten]

Try

sol = ode45(@(t,y)first(t,v,ABP(i)),[0 100], [0;0;0;0;0.205;97.6;12;49.67]);

Best wishes

Torsten.

[gorilla3]

Thank you for your reply, Torsten.

However, by substituting that I get the error:

Undefined function or variable 'v'.

Error in CBF_2006_f_v11>@(t,y)first(t,v,ABP(i))

Error in odearguments (line 90)
f0 = feval(ode,t0,y0,args{:});   % ODE15I sets args{1} to yp0.

Error in ode45 (line 115)
    odearguments(FcnHandlesUsed, solver_name, ode, tspan, y0, options, varargin);

Error in CBF_2006_f_v11 (line 10)
      sol = ode45(@(t,y)first(t,v,ABP(i)),[0 100], [0;0;0;0;0.205;97.6;12;49.67]);

[Star Strider]

I believe Torsten intended:

sol = ode45(@(t,v)first(t,v,ABP(i)),[0 100], [0;0;0;0;0.205;97.6;12;49.67]);

[Torsten]

Thank you, Star.

[gorilla3]

Thanks but that still doesn't solve the issue of the for loop not moving forward. I get the same output as in the original code I posted above.

[Torsten]

Before you use the loop, you should be almost sure that the solver manages to integrate your system for the parameters given.

So first test for single values of ABP what the problem is. A good starting point would thus be abp = 40.

Best wishes

Torsten.